Articoli di riviste: "Guides à modes lents"

1

Elissalde, Bernard. "Guides, modes d'emploi". Espaces Temps 33, n. 1 (1986): 27–30. http://dx.doi.org/10.3406/espat.1986.3316.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

2

Vassallo, Charles. "Pseudo-modes et guides optiques". Annales des Télécommunications 43, n. 1-2 (gennaio 1988): 48–65. http://dx.doi.org/10.1007/bf02995071.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

3

Egorov, A. A., K. P. Lovetsky, A. L. Sevastianov e L. A. Sevastianov. "Thin-film waveguide L¨uneburg lens in the model of adiabatic guided modes". Mathematical Modelling and Geometry 11, n. 2 (2 novembre 2023): 1–12. http://dx.doi.org/10.26456/mmg/2023-1121.

Testo completo

Abstract (sommario):

A mathematical model is presented that describes the processes of propagation and transformation of coherent electromagnetic radiation in a multilayer three-dimensional (3D) smoothly irregular integrated optical waveguide, called the model of adiabatic guided modes. Its presentation and individual applications in smoothly irregular integrated optical waveguides contain two short stories: • two-dimensional evolution of guided modes is described; • boundary conditions are formed on non-horizontal planes tangent to media interfaces, which lead to the description of hybridization of guided modes and other interesting phenomena. The model of adiabatic guided modes generalizes the cross-section method (reference waveguide method) with nonlocal boundary conditions for the transverse guided mode operator in the reference waveguide cross section to the case of twodimensional evolution, leading to the description of a number of new effects.

Gli stili APA, Harvard, Vancouver, ISO e altri

4

Istomin, A. B., A. V. Lyubimtseva e V. O. Dmitriev. "Research of linear guides of metal-cutting machines". Glavnyj mekhanik (Chief Mechanic), n. 11 (1 novembre 2020): 53–65. http://dx.doi.org/10.33920/pro-2-2011-08.

Testo completo

Abstract (sommario):

The article discusses the guides used in metal-cutting machines. The advantages and disadvantages of sliding guides with different modes of friction and rolling guides with different types of rolling bodies are studied in detail. Recommendations for using each type of guide are given, and examples are considered.

Gli stili APA, Harvard, Vancouver, ISO e altri

5

Linton, C. M., M. McIver, P. McIver, K. Ratcliffe e J. Zhang. "Trapped modes for off-centre structures in guides". Wave Motion 36, n. 1 (giugno 2002): 67–85. http://dx.doi.org/10.1016/s0165-2125(02)00006-9.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

6

Bonnet, A. "Guided modes of integrated optical guides. A mathematical study". IMA Journal of Applied Mathematics 60, n. 3 (1 giugno 1998): 225–61. http://dx.doi.org/10.1093/imamat/60.3.225.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

7

Ruppen, Hans-Jörg. "Multiple TE-modes for planar, self-focusing wave guides". Annali di Matematica Pura ed Applicata 172, n. 1 (dicembre 1997): 323–77. http://dx.doi.org/10.1007/bf01782618.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

8

Helke, Christian, Markus Reinhardt, Markus Arnold, Falk Schwenzer, Micha Haase, Matthias Wachs, Christian Goßler et al. "On the Fabrication and Characterization of Polymer-Based Waveguide Probes for Use in Future Optical Cochlear Implants". Materials 16, n. 1 (22 dicembre 2022): 106. http://dx.doi.org/10.3390/ma16010106.

Testo completo

Abstract (sommario):

Improved hearing restoration by cochlear implants (CI) is expected by optical cochlear implants (oCI) exciting optogenetically modified spiral ganglion neurons (SGNs) via an optical pulse generated outside the cochlea. The pulse is guided to the SGNs inside the cochlea via flexible polymer-based waveguide probes. The fabrication of these waveguide probes is realized by using 6” wafer-level micromachining processes, including lithography processes such as spin-coating cladding layers and a waveguide layer in between and etch processes for structuring the waveguide layer. Further adhesion layers and metal layers for laser diode (LD) bonding and light-outcoupling structures are also integrated in this waveguide process flow. Optical microscope and SEM images revealed that the majority of the waveguides are sufficiently smooth to guide light with low intensity loss. By coupling light into the waveguides and detecting the outcoupled light from the waveguide, we distinguished intensity losses caused by bending the waveguide and outcoupling. The probes were used in first modules called single-beam guides (SBGs) based on a waveguide probe, a ball lens and an LD. Finally, these SBGs were tested in animal models for proof-of-concept implantation experiments.

Gli stili APA, Harvard, Vancouver, ISO e altri

9

Бишутин, Сергей, e Sergey Bishutin. "Quality and wear-resistance of friction surfaces in extended cylindrical guides after combined anti-friction treatment". Science intensive technologies in mechanical engineering 2018, n. 11 (8 dicembre 2018): 19–24. http://dx.doi.org/10.30987/article_5bd8aa88d29f01.40920939.

Testo completo

Abstract (sommario):

The results of investigations of surface quality and wear-resistance in extended cylindrical guides worked according to a new technology of anti-friction treatment are shown. The design of a combined tool developed is considered. There are presented technological modes of surface treatment and the results of tribo-technical tests of guides.

Gli stili APA, Harvard, Vancouver, ISO e altri

10

Barnes, C., B. L. Johnson e G. Kirczenow. "Introducing directionality to Anderson localization: The transport properties of quantum railroads". Canadian Journal of Physics 72, n. 9-10 (1 settembre 1994): 559–67. http://dx.doi.org/10.1139/p94-071.

Testo completo

Abstract (sommario):

We present a study of the transport properties of a general class of quantum mechanical wave guides: quantum railroads (QRR). These wave guides are characterized by having adiabatic modes that carry current along the wave guide in opposite directions; for example N forward modes and M reverse modes. Anderson localization and the integer quantum Hall effect are characteristic of the disordered N = M and M = 0 cases, respectively. We consider the general case of arbitrary N and M, and show that it can be understood in terms of directed localization. Thus, we unify the theories of Anderson localization and the integer quantum Hall effect and demonstrate how they fit into a broader conceptual framework. We find that in any QRR there are always [Formula: see text] perfectly transmitted effective adiabatic modes with the remainder being subject to multiple scattering and interference effects characteristic of the N = M case.

Gli stili APA, Harvard, Vancouver, ISO e altri

11

MÖLLERING, MARTINA. "Computer mediated communication: learning German online in Australia". ReCALL 12, n. 1 (maggio 2000): 27–34. http://dx.doi.org/10.1017/s0958344000000410.

Testo completo

Abstract (sommario):

This article investigates the use of computer-mediated communication technologies in the context of teaching German by distance mode in Australia. More conventional delivery modes such as audiocassettes and printed study guides were augmented by electronic support mechanisms. Students were able to access their study guides, timetables and assignment tasks online and communicated with their course convener as well as with fellow students via a bulletin board and an internal email system set up for the course. The article reports on the extent to which students used these facilities rather than more conventional modes of communication (fax., telephone, written submission of assignments), on how students managed the set tasks and what difficulties they encountered.

Gli stili APA, Harvard, Vancouver, ISO e altri

12

Aboura, Z., e B. Bouhafs. "Geometry of Waves Guides for Containment of Propagating Resonant Modes". Journal of Fundamental and Applied Sciences 3, n. 1 (3 settembre 2015): 68. http://dx.doi.org/10.4314/jfas.v3i1.7.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

13

McIver, P., C. M. Linton e M. McIver. "Construction of trapped modes for wave guides and diffraction gratings". Proceedings of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences 454, n. 1978 (8 ottobre 1998): 2593–616. http://dx.doi.org/10.1098/rspa.1998.0272.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

14

Zhou, Jingxuan, Jie Zhang, Jiahui Chang, Zheng-Yang Li e Dongjia Yan. "Active Control Topological Valley Modes in Metamaterial Plates". Crystals 13, n. 6 (10 giugno 2023): 933. http://dx.doi.org/10.3390/cryst13060933.

Testo completo

Abstract (sommario):

Phononic crystals and metamaterials have a unique band structure that allows for the existence of topologically protected surface states. The topologically protected edge states can guide elastic waves without significant scattering or loss of energy. One of the most promising applications of topological insulators in wave guiding is in the field of acoustics, where they can be used to design highly efficient and robust acoustic wave guides. However, the high efficiency, precision, reconfigurability, and robustness of elastic waves remains challenging. The topological insulators provide a feasible method to design high-efficiency, robust, and low-backscattering waveguides. In this work, a novel design of hexagonal metamaterial plates composed of a base plate and piezoelectric patches is proposed. The hexagonal metamaterial plate can generate robust topologically protected edge waves via active control. The paths of the topologically protected edge waves can be tuned by adjusting the control parameters. The robustness and efficiency of the proposed hexagonal metamaterial plate are testified to by the numerical examples. These findings provide systematic theoretical guidelines for designing reconfigurable wave guides, elastic wave splitters, and novel elastic wave devices and hold great promise for the development of high-performance and versatile wave guide technologies with potential applications in a wide range of fields.

Gli stili APA, Harvard, Vancouver, ISO e altri

15

Ursel, Karen L. "Minding the Gap: The Art and Science of Teaching Guided by Humanbecoming". Nursing Science Quarterly 33, n. 4 (17 settembre 2020): 322–29. http://dx.doi.org/10.1177/0894318420943138.

Testo completo

Abstract (sommario):

Designing learning activities to teach psychomotor skills utilizing the lens of humanbecoming required deep reflection on the principles of structuring meaning, configuring rhythmical patterns, and cotranscending with possibles to bridge the theory-to-practice gap. Teaching essential psychomotor skills presented a challenge when trying to ensure the provision of safe, competent, and compassionate care tailored to the individual’s unique experience. There are a wide variety of teaching approaches and strategies available, but few have used a theoretical framework to guide the design of the teaching-learning activities to guide development of these skills. The humanbecoming paradigm and humanbecoming teaching-learning model guided the research, design, and presentation of the teaching-learning activities to encompass the science and performing art of nursing.

Gli stili APA, Harvard, Vancouver, ISO e altri

16

Mennesson, Christine, e Romain Galissaire. "Les femmes guides de haute montagne : modes de socialisation et identités sexuées". Articles 17, n. 1 (29 ottobre 2004): 111–41. http://dx.doi.org/10.7202/009298ar.

Testo completo

Abstract (sommario):

Résumé Cet article analyse les modes d’engagement et les identités sexuées des dix femmes exerçant le métier de guide de haute montagne en France. Deux modes de découverte des activités de montagne ainsi qu’une socialisation sexuée enfantine au sein du groupe des pairs masculins favorisent l’investissement des femmes dans les pratiques sportives de haute montagne. Par ailleurs, si les femmes guides partagent une vision globalement négative des femmes au foyer comme des militantes féministes, elles se réfèrent néanmoins à des formes identitaires différentes pour se définir.

Gli stili APA, Harvard, Vancouver, ISO e altri

17

Al-awfi, S., e M. Babiker. "Field-dipole orientation mechanism and higher order modes in atom guides". Journal of Modern Optics 48, n. 5 (aprile 2001): 847–58. http://dx.doi.org/10.1080/09500340108230956.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

18

Matsui, Takayuki, Shuichi Yamashita, Hiroyuki Wado, Hisayoshi Fujikawa e Hideo Iizuka. "Flat grating lens utilizing widely variable transmission-phase via guided-modes". Optics Letters 40, n. 1 (17 dicembre 2014): 25. http://dx.doi.org/10.1364/ol.40.000025.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

19

Choudhury, P. K. "Evanescent Field Enhancement in Liquid Crystal Optical Fibers: A Field Characteristics Based Analysis". Advances in Condensed Matter Physics 2013 (2013): 1–9. http://dx.doi.org/10.1155/2013/504868.

Testo completo

Abstract (sommario):

The paper presents the analysis of the electromagnetic wave propagation through liquid crystal optical fibers (LCOFs) of two different types—conventional guides loaded with liquid crystals (addressed as LCOFs) and those with additional twists due to conducting helical windings (addressed as HCLCOFs). More precisely, the three-layer optical waveguide structures are considered along with its outermost region being loaded with radially anisotropic liquid crystal material and the inner regions being made of usual silica, as used in conventional optical fibers. In addition to that, LCOF with twists introduced in the form of conducting helical windings at the interface of the silica core and the liquid crystal clad is also taken into account. Emphasis has been put on the power confinements by the lower-order TE modes sustained in the different sections of the LCOF structure. The results demonstrate useful applications of these guides in integrated optics as the power sustained in the liquid crystal section by the excited TE modes remains very high. In the case of twisted clad liquid crystal guides, descriptions are limited to the nature of dispersion relation only under the TE mode excitation, and corresponding to the cases of helix orientations being parallel and perpendicular to the optical axis.

Gli stili APA, Harvard, Vancouver, ISO e altri

20

Datti, Yusuf Umar, Noor Amila Wan Abdullah Zawawi, Abdullahi Ahmed Umar, Muslich Hartadi Sutanto e Kamaluddeen Usman Danyaro. "Challenges of Maturity Models in Public-Private Partnerships (PPPs) in the Post-COVID-19 Era". Journal of Engineering, Project, and Production Management 12, n. 2 (1 maggio 2022): 149–65. http://dx.doi.org/10.32738/jeppm-2022-0014.

Testo completo

Abstract (sommario):

Maturity models (MMs) have witnessed exponential increase due to their successful application in several domains. However, there is an absence of review that guides researchers in developing, applying and validating Public-Private Partnership maturity models (PPPMMs). This study examines PPPMMs, provides guidance on the topic and highlights gaps in the literature. A literature search on selected electronic databases was conducted, and the study adopted the widely accepted Preferred Reporting Items for Systematic Review and Meta-analysis statement (PRISMA). The study identified a total of four thousand six hundred and eighteen (4,618) studies, and twenty-one studies (21Nr) were rigorously selected. The results revealed PPPMMs as an emerging area of research with a low number – 21 publications since its deployment for about two (2) decades. Similarly, the findings unveiled a lack of uniformity in conceptualising the terms, dimensions used, and methodology adopted. This finding is attributed mainly to the limited use of the theoretical lens, which considerably weakens the model’s theoretical foundation and limits its potential to guide improvement. Additionally, there are more efforts in developing MMs than applying and validating them. Furthermore, there is an unbalanced focus on descriptive models over prescriptive and comparative models, which inhibit the model’s potential to guide improvement. Future work should provide a solid ground to the field using a theoretical lens and focus on prescriptive models with a strong emphasis on application and validation. This research is the first of its kind that synthesises and brings together available PPPMMs literature into one place. It also contributes to the body of knowledge by highlighting areas of research that require immediate attention to enhance the much-needed success of PPP in the post-COVID-19 era.

Gli stili APA, Harvard, Vancouver, ISO e altri

21

Mennesson, Christine. "Les femmes guides de haute montagne : modes d'engagement et rapports au métier". Travail, genre et sociétés N° 13, n. 1 (2005): 117. http://dx.doi.org/10.3917/tgs.013.0117.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

22

Mohamed, Hassan Ahmed Hassan. "Integrated Enterprise Resilience Architecture Framework for Surviving Strategic Disruptions". Enterprise Risk Management 4, n. 1 (25 novembre 2018): 35. http://dx.doi.org/10.5296/erm.v4i1.13716.

Testo completo

Abstract (sommario):

Resilient business enterprises are able to survive strategic disruptions like technology disruptions and come back more successful. They succeed because they develop and effectively implement the resilience strategies of mitigation, adaption, and transformation. This paper proposes an integrated resilience framework that is based on a combination of enterprise architecture and business architecture frameworks. At the core of the proposed framework is a meta-model and a method. The framework guides the development of a unified vision of how a business enterprise can address a specific strategic disruption and transform itself in a successful way. The framework articulates the vision through the lens of business blueprint views that guide the formation of transformation initiatives. Through the mapping capabilities of the framework, the transformation initiatives cross over the boundaries between organization structures and domains. In the last section we demonstrate our proposed method and meta-model with the help of a case study.

Gli stili APA, Harvard, Vancouver, ISO e altri

23

Малыкин, Г. Б., e В. И. Позднякова. "Точные решения для локальных параметров поляризационных мод в намотанных на катушку spun-световодах с сильным невозмущенным линейным двулучепреломлением. I. Нерезонансная линейная трансформация". Журнал технической физики 127, n. 12 (2019): 937. http://dx.doi.org/10.21883/os.2019.12.48689.210-19.

Testo completo

Abstract (sommario):

The propagation of monochromatic radiation is considered in coiled spun-light guides. It is shown that the local parameters of the elliptic polarization modes, the elliptical birefringence and the angle of ellipticity, are the sum of the constant and variable components. The latter varying in accordance with the harmonic law of the fiber length and the magnitudes of the constant components are substantially larger than the amplitudes of the variable components. It is also shown that the dependence of the local azimuth of the ellipse major axis of eigenpolarization modes increases almost linearly.

Gli stili APA, Harvard, Vancouver, ISO e altri

24

Schoenemann, B., e E. N. K. Clarkson. "Light guide lenses in trilobites?" Earth and Environmental Science Transactions of the Royal Society of Edinburgh 102, n. 1 (marzo 2011): 17–23. http://dx.doi.org/10.1017/s1755691011010097.

Testo completo

Abstract (sommario):

ABSTRACTThree main types of eye have been defined in trilobites; holochroal, schizochroal and the rare abathochroal. At least in holochroal and schizochroal eyes, the lenses consist of oriented calcitic microcrystallites, the so-called trabecula, which run uninterruptedly throughout the lens from top to bottom. It is argued here that these are primary structures and not diagenetic. Holochroal eyes are commonly accepted to correspond to apposition eyes, which are the most common type of compound eyes in arthropods living today. Schizochroal eyes, present only in phacopine trilobites, are characterised by a doublet lens structure, with an aplanatic interface, correcting spherical aberration of the thick lenses to form a sharp focus for incident rays travelling parallel with the optical axis. This classic model seems to be functional for many phacopines. In these the trabecula are present, though all juxtaposed, forming a solid block. In the lenses of some phacopid species, however, the microcrystallites are separated from each other by gaps. If, during life, these gaps were filled with organic material, as the lens grew from the larval stages, or post-ecdysially, each trabeculum would be isolated from its neighbours by an organic sheath. A simple model is proposed here for the generation of the organic sheath surrounding each trabeculum. If the individual trabecula were isolated from each other, then the possibility of a new kind of visual system exists in these ‘derived’ phacopines. The differences between the refractive indexes inside and outside the trabeculum would ensure that each trabeculum acted as a light-guide, so that the whole ‘lens’ becomes a light guide bundle. This would result in a pixelled visual system, unique in the animal realm, but an archetype for modern technology of data transfer.

Gli stili APA, Harvard, Vancouver, ISO e altri

25

Jia, Peizhi, Bin Zhang, Qibo Feng e Fajia Zheng. "Simultaneous Measurement of 6DOF Motion Errors of Linear Guides of CNC Machine Tools Using Different Modes". Sensors 20, n. 12 (18 giugno 2020): 3439. http://dx.doi.org/10.3390/s20123439.

Testo completo

Abstract (sommario):

Based on the prior work on the six degrees of freedom (6DOF) motion errors measurement system for linear axes, and for the different types of machine tools and different installation methods, this study used a ray tracing idea to establish the measurement models for two different measurement modes: (1) the measurement head is fixed and the target mirror moves and (2) the target mirror is fixed and the measurement head moves. Several experiments were performed on the same linear guide using two different measurement modes. The comparative experiments show that the two measurement modes and their corresponding measurement models are correct and effective. In the actual measurement process, it is therefore possible to select the corresponding measurement model according to the measurement mode. Furthermore, the correct motion error evaluation results can be obtained.

Gli stili APA, Harvard, Vancouver, ISO e altri

26

Bondi, Roberta C. "The Abba and Amma in Early Monasticism: The First Pastoral Counselors?" Journal of Pastoral Care 40, n. 4 (dicembre 1986): 311–20. http://dx.doi.org/10.1177/002234098604000405.

Testo completo

Abstract (sommario):

Sketches desert monasticism of the late third century and the key roles played by the Abba and Amma in the development of early monasticism. Outlines the assumptions of these guides and gives brief illustrations of their modes of counsel and direction, some of which parallel certain assumptions and practices of the modern pastoral counselor.

Gli stili APA, Harvard, Vancouver, ISO e altri

27

Oliver, Debra Parker, Davina Porock e David B. Oliver. "Managing the Secrets of Dying Backstage: The Voices of Nursing Home Staff". OMEGA - Journal of Death and Dying 53, n. 3 (novembre 2006): 193–207. http://dx.doi.org/10.2190/3p8g-5jad-j2nf-bkgk.

Testo completo

Abstract (sommario):

The project analyzed staff descriptions of undocumented care given to dying nursing home residents. Registered nurses, licensed practical nurses, certified nurse aids, and social service designees were interviewed using an unstructured interview guide. Transcripts were coded by two members of the team and a thematic analysis was guided with the theoretical framework of Erving Goffman's dramaturgical model of social interaction. Analysis of interview transcripts revealed practices related to end of life care that went undocumented. Viewed through the lens of Goffman's theoretical model, this undocumented care revealed “secrets” related to socialization processes, communication, tension, superstitions, and interactions between staff and dying residents. Findings show that while dying is not formally acknowledged in the nursing home setting, staff experiences the reality of death and informally responds to the special needs of residents.

Gli stili APA, Harvard, Vancouver, ISO e altri

28

Fourie, Ina. "Models and theories that can guide grief and bereavement information interventions: an information behaviour lens". Information Research an international electronic journal 29, n. 2 (18 giugno 2024): 302–21. http://dx.doi.org/10.47989/ir292828.

Testo completo

Abstract (sommario):

Introduction. Information behaviour in grief, bereavement, death, dying and its influence on the development of information interventions is understudied. Although pragmatic and evidence-based practices work well, theoretical and conceptual models, research findings and theories should inform grief and bereavement information interventions developed by specialist counsellors. Extensive literature on death, dying, grief and bereavement counselling/therapy and information behaviour per se, does not address this need. This paper reports on work in progress exploring existing theories and models that might guide research. Method. Scoping review of literature from applicable disciplines (health, social work, religion, psychology, library/information science) for theories/models reported in grief and bereavement counselling and bereavement information intervention design. The focus is on information behaviour and all related information activities. Analysis. Two tables based on a content analysis that show theories/models that hold value for information interventions and studies of information behaviour. Results. The analysis reveals a spectrum of theories including grief theory, grief stage theory, theory of motivated information management. Models for consideration include bereavement model, transtheoretical model (narratives), social interaction model. Conclusion. Information behaviour research should continue to strive in conceptually and theoretically informing grief and bereavement information interventions, practices and work in grief and bereavement counselling.

Gli stili APA, Harvard, Vancouver, ISO e altri

29

Raney, Catie A., Charles R. Keeton e Dhruv T. Zimmerman. "A new framework for understanding systematic errors in cluster lens modelling – I. Selection and treatment of cluster member galaxies". Monthly Notices of the Royal Astronomical Society 508, n. 4 (6 ottobre 2021): 5587–601. http://dx.doi.org/10.1093/mnras/stab2857.

Testo completo

Abstract (sommario):

ABSTRACT With high-quality data from programs like the Hubble Frontier Fields, cluster lensing has reached the point that models are dominated by systematic rather than statistical uncertainties. We introduce a Bayesian framework to quantify systematic effects by determining how different lens modelling choices affect the results. Our framework includes a new two-sample test for quantifying the difference between posterior probability distributions that are sampled by methods like Monte Carlo Markov chains. We use the framework to examine choices related to the selection and treatment of cluster member galaxies in two of the Frontier Field clusters: Abell 2744 and MACS J0416.1–2403. When selecting member galaxies, choices about depth and area affect the models; we find that model results are robust for an I-band magnitude limit of mlim ≥ 22.5 mag and a radial cut of rlim ≥ 90 arcsec (from the centre of the field), although the radial limit likely depends on the spatial extent of lensed images. Mass is typically assigned to galaxies using luminosity/mass scaling relations. We find that the slopes of the scaling relations can have significant effects on lens model parameters but only modest effects on lensing magnifications. Interestingly, scatter in the scaling relations affects the two fields differently. This analysis illustrates how our framework can be used to analyse lens modelling choices and guide future cluster lensing programs.

Gli stili APA, Harvard, Vancouver, ISO e altri

30

Raney, Catie A., Charles R. Keeton e Dhruv T. Zimmerman. "A new framework for understanding systematic errors in cluster lens modelling – I. Selection and treatment of cluster member galaxies". Monthly Notices of the Royal Astronomical Society 508, n. 4 (6 ottobre 2021): 5587–601. http://dx.doi.org/10.1093/mnras/stab2857.

Testo completo

Abstract (sommario):

ABSTRACT With high-quality data from programs like the Hubble Frontier Fields, cluster lensing has reached the point that models are dominated by systematic rather than statistical uncertainties. We introduce a Bayesian framework to quantify systematic effects by determining how different lens modelling choices affect the results. Our framework includes a new two-sample test for quantifying the difference between posterior probability distributions that are sampled by methods like Monte Carlo Markov chains. We use the framework to examine choices related to the selection and treatment of cluster member galaxies in two of the Frontier Field clusters: Abell 2744 and MACS J0416.1–2403. When selecting member galaxies, choices about depth and area affect the models; we find that model results are robust for an I-band magnitude limit of mlim ≥ 22.5 mag and a radial cut of rlim ≥ 90 arcsec (from the centre of the field), although the radial limit likely depends on the spatial extent of lensed images. Mass is typically assigned to galaxies using luminosity/mass scaling relations. We find that the slopes of the scaling relations can have significant effects on lens model parameters but only modest effects on lensing magnifications. Interestingly, scatter in the scaling relations affects the two fields differently. This analysis illustrates how our framework can be used to analyse lens modelling choices and guide future cluster lensing programs.

Gli stili APA, Harvard, Vancouver, ISO e altri

31

Kane, Maurice J. "Professional adventure tourists: Producing and selling stories of ‘authentic’ identity". Tourist Studies 12, n. 3 (10 ottobre 2012): 268–86. http://dx.doi.org/10.1177/1468797612461087.

Testo completo

Abstract (sommario):

The ability to experience distinctive adventure appears limited today in comparison to the accounts of past exploring heroes. Even with these perceived limitations, there is continued growth in remote adventure tours. Guided by a Bourdieusian lens, this article examines the negotiation of authenticity, distinction and identity in the websites and blogs of companies and tourists during the 2010 spring Mt Everest climbing season. The interpretation suggests company blogs offer tourists an experience framed in mountaineering myth. The mountaineering guides’ capital derived from skill, experience and decision making ability make this experience possible. The tourists’ blogs offer authentically, recognisable environments, practices, and emotions disguising their limited mountaineering abilities. Tourist’s existential stories seek to transcend and appropriate mountaineering capital. For the females in this study, tour experience has supported careers based on mountaineering adventurer social identities. The companies’ tourism products facilitate the professional adventure tourist’s role model claims to ‘authentic’ adventurer identities.

Gli stili APA, Harvard, Vancouver, ISO e altri

32

LI Rui, 李蕊, 刘永基 LIU Yong-ji e 王肇圻 WANG Zhao-qi. "Design of wavefront-guided lens based on individual eye optical model". Chinese Journal of Optics and Applied Optics 5, n. 5 (2012): 512–19. http://dx.doi.org/10.3788/co.20120505.0512.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

33

Stone, Robert B., Irem Y. Tumer e Michael Van Wie. "The Function-Failure Design Method". Journal of Mechanical Design 127, n. 3 (12 luglio 2004): 397–407. http://dx.doi.org/10.1115/1.1862678.

Testo completo

Abstract (sommario):

To succeed in the product development market today, firms must quickly and accurately satisfy customer needs while designing products that adequately accomplish their desired functions with a minimum number of failures. When failure analysis and prevention are coupled with a product’s design from its conception, potentially shorter design times and fewer redesigns are necessary to arrive at a final product design. In this article, we explore the utility of a novel design methodology that allows failure modes and effects analysis (FMEA)-style failure analysis to be conducted during conceptual design. The function-failure design method (FFDM) guides designers towards improved designs by predicting likely failure modes based on intended product functionality.

Gli stili APA, Harvard, Vancouver, ISO e altri

34

Florjaāczyk, M., e R. Tremblay. "Tapered optical couplers with grating: Beyond the weak-guidance limit". Canadian Journal of Physics 71, n. 1-2 (1 gennaio 1993): 5–10. http://dx.doi.org/10.1139/p93-002.

Testo completo

Abstract (sommario):

We describe the operation of a grating-assisted optical coupler consiting of two different curved slab wave guides. A version of vectorial, nonorthogonal coupled-mode theory based on local modes is applied. The coupled-mode equations contain mode overlap terms and coupling terms, which vary with distance. These equations are solved numerically for even-transverse magnetic modes propagating in the non-weakly guided slabs. We show output light powers as a function of the input wavelength assuming a condition of contradirectional coupling. For comparison we also show the result in the limit of weak guidance and a result from the vectorial theory without mode overlaps.

Gli stili APA, Harvard, Vancouver, ISO e altri

35

Stukalova, A. A. "Library e-catalogs: The current state and modes". Scientific and Technical Libraries, n. 4 (26 aprile 2022): 105–25. http://dx.doi.org/10.33186/1027-3689-2022-4-105-125.

Testo completo

Abstract (sommario):

Modern functionality of library e-catalogs and union catalogs is discussed. The e-catalogs are examined for the features of new generation. However, many features are lacking in e-catalogs. Almost all e-catalogs under examinations are comfortable for use and feature facet navigation, several search modes, instructions and search guides. On the other hand, not many e-catalogs cover the library collection completely, and have to be checked for spelling. Just few ecatalogs offer fonts for visually impaired people, recommendations orthe possibility to add information to bibliographic records. Definitely, e-catalog bibliographic records comprise additional information, i. e. book cover images, annotations, and less frequently – lists of contents. However, as a rule, this data is included into blbliographic records of modern publications. Many e-catalogs comprise full texts or links to full texts. The study findings evidence on the need to improve ecatalog functionality to offer users more powerful and attractive search tools.

Gli stili APA, Harvard, Vancouver, ISO e altri

36

Stukalova, A. A. "Library e-catalogs: The current state and modes". Scientific and Technical Libraries, n. 4 (26 aprile 2022): 105–25. http://dx.doi.org/10.33186/1027-3689-2022-4-105-125.

Testo completo

Abstract (sommario):

Modern functionality of library e-catalogs and union catalogs is discussed. The e-catalogs are examined for the features of new generation. However, many features are lacking in e-catalogs. Almost all e-catalogs under examinations are comfortable for use and feature facet navigation, several search modes, instructions and search guides. On the other hand, not many e-catalogs cover the library collection completely, and have to be checked for spelling. Just few ecatalogs offer fonts for visually impaired people, recommendations orthe possibility to add information to bibliographic records. Definitely, e-catalog bibliographic records comprise additional information, i. e. book cover images, annotations, and less frequently – lists of contents. However, as a rule, this data is included into blbliographic records of modern publications. Many e-catalogs comprise full texts or links to full texts. The study findings evidence on the need to improve ecatalog functionality to offer users more powerful and attractive search tools.

Gli stili APA, Harvard, Vancouver, ISO e altri

37

Baqir, M. A., e P. K. Choudhury. "Flux Density through Guides with Microstructured Twisted Clad DB Medium". Journal of Nanomaterials 2014 (2014): 1–6. http://dx.doi.org/10.1155/2014/629651.

Testo completo

Abstract (sommario):

The paper deals with the study of flux density through a newly proposed twisted clad guide containing DB medium. The inner core and the outer clad sections are usual dielectrics, and the introduced twisted windings at the core-clad interface are treated under DB boundary conditions. The pitch angle of twist is supposed to greatly contribute towards the control over the dispersion characteristics of the guide. The eigenvalue equation for the guiding structure is deduced, and the analytical investigations are made to explore the propagation patterns of flux densities corresponding to the sustained low-order hybrid modes under the situation of varying pitch angles. The emphasis has been put on the effects due to the DB twisted pitch on the propagation of energy flux density through the guide.

Gli stili APA, Harvard, Vancouver, ISO e altri

38

Zimmerman, Dhruv T., Charles R. Keeton e Catie A. Raney. "A new framework for understanding systematic errors in cluster lens modelling – II. Constraint selection". Monthly Notices of the Royal Astronomical Society 508, n. 4 (6 ottobre 2021): 5602–11. http://dx.doi.org/10.1093/mnras/stab2858.

Testo completo

Abstract (sommario):

ABSTRACT Cluster lens models are affected by a variety of choices in the lens modelling process. We have begun a programme to develop a systematic error budget for cluster lens modelling. Here, we examine the selection of image constraints as a potential systematic effect. For constraining the mass model, we find that it is more important to have images be spatially distributed around the cluster than to have them distributed in redshift. We also find that some image sets appear to be more important than others in terms of how well they constrain the models; the ‘important’ image sets typically include an image that lies close to a lensing critical curve as well as an image that is relatively isolated from other images (providing constraints in a region that would otherwise lack lensing information). These conclusions can help guide observing programmes that seek follow-up data for candidate lensed images.

Gli stili APA, Harvard, Vancouver, ISO e altri

39

Zimmerman, Dhruv T., Charles R. Keeton e Catie A. Raney. "A new framework for understanding systematic errors in cluster lens modelling – II. Constraint selection". Monthly Notices of the Royal Astronomical Society 508, n. 4 (6 ottobre 2021): 5602–11. http://dx.doi.org/10.1093/mnras/stab2858.

Testo completo

Abstract (sommario):

ABSTRACT Cluster lens models are affected by a variety of choices in the lens modelling process. We have begun a programme to develop a systematic error budget for cluster lens modelling. Here, we examine the selection of image constraints as a potential systematic effect. For constraining the mass model, we find that it is more important to have images be spatially distributed around the cluster than to have them distributed in redshift. We also find that some image sets appear to be more important than others in terms of how well they constrain the models; the ‘important’ image sets typically include an image that lies close to a lensing critical curve as well as an image that is relatively isolated from other images (providing constraints in a region that would otherwise lack lensing information). These conclusions can help guide observing programmes that seek follow-up data for candidate lensed images.

Gli stili APA, Harvard, Vancouver, ISO e altri

40

Mirzaei, Hassan, Rubaiyat Islam e George V. Eleftheriades. "Anomalous Negative Group Velocity in Coupled Positive-Index/Negative-Index Guides Supporting Complex Modes". IEEE Transactions on Antennas and Propagation 59, n. 9 (settembre 2011): 3412–20. http://dx.doi.org/10.1109/tap.2011.2161558.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

41

Tseng, Wen-Ta, Hsing-Fu Cheng e Xuesong (Andy) Gao. "Validating a Motivational Self-Guide Scale for Language Learners". Sustainability 12, n. 16 (11 agosto 2020): 6468. http://dx.doi.org/10.3390/su12166468.

Testo completo

Abstract (sommario):

The aim of the current study was to develop and validate a new instrument that taps into learners’ self-image as a means of exploring language motivation, which plays a pivotal role in sustaining language learners’ efforts. A critical review of the literature revealed that the current measures of the second language (L2) self-guide instruments in language learning motivation research suffered from either under-representativeness of the ought-to L2 selfothers or weak validity of the ideal L2 selfown. Since multilingualism has become more salient in foreign language education, it was necessary to develop a measurement that could better reflect self-imagery which was both plausible and relevant in foreign language contexts. This study utilized four scales in total that tapped into the targeted latent constructs: ideal L2 selfown, ideal L2 selfothers, ought-to L2 selfown, and ought-to L2 selfothers. Two independent samples recruited from Taiwanese college students were employed in the study. After an item-pool was developed through interviewing and piloting, each subscale was comprised of 4 items, totaling 16 items for formal model testing. The formal model testing involved three phases. Phase I conducted an exploratory factor analysis to explore the possible dimensions using the first sample. Phase II proceeded with a series of confirmatory factor analysis (CFA) on the eight hypothesized models using the second sample. Phase III also relied on the second sample and further examined the item fit performance by using the multidimensional Rasch model. The results of formal model testing confirmed the validity and reliability of a 4-factor correlated model, as well as the fit performance of the finalized scale items, and thus lent strong empirical support to Higgins’s theory regarding the inner structure of future self-guides. It is suggested that the new L2 self-guide scale can be adopted and applied to future L2 and languages other than English motivational research.

Gli stili APA, Harvard, Vancouver, ISO e altri

42

Wang, Yu Ning, e Li Jian Ren. "Research on Land Exploitation and Utilization Guided by Urban Rail Transit". Advanced Materials Research 450-451 (gennaio 2012): 1207–10. http://dx.doi.org/10.4028/www.scientific.net/amr.450-451.1207.

Testo completo

Abstract (sommario):

Under the background of rapid development of urban rail transit, how it effectively guides land exploitation and utilization becomes the key of urban land exploitation. Based upon the analysis of the land exploitation modes guided by urban rail transit home and abroad, this paper compares and analysis the relevant factors of land exploitation guided by urban rail transit, and proposes some suggestions for the land exploitation and utilization guided by urban rail transit in China.

Gli stili APA, Harvard, Vancouver, ISO e altri

43

Hänninen, Vilma. "A model of narrative circulation". Narrative Inquiry 14, n. 1 (1 luglio 2004): 69–85. http://dx.doi.org/10.1075/ni.14.1.04han.

Testo completo

Abstract (sommario):

This article suggests that narrative meaning structures have different modes of existence: the “told”, the “inner” and the “lived” modes. Their definitions and mutual relationships are presented in the form of a schematic model. The inner narrative represents the experiental mode of narrative form. It is an individual's interpretation of his/her life, in which the past events, present situation and future projects are understood using cultural narrative models as resources. It is (partly) made external by told narratives, and validated/revised in that process. The lived narrative, again, refers to the real-life drama, which is shaped in the interplay between situational constraints and the inner narrative that guides one's actions in changing life situations. The article reviews narrative research focusing on the studies and discussions related to the relations between the different modes of narrativity. (Narrative Theory, Narrative Methodology, Inner Narrative, Lived Narrative)

Gli stili APA, Harvard, Vancouver, ISO e altri

44

Choudhury, P. K. "Dispersion Behavior of Gold-Nanocoated Dielectric Optical Fibers". Advances in Materials Science and Engineering 2012 (2012): 1–7. http://dx.doi.org/10.1155/2012/214614.

Testo completo

Abstract (sommario):

Using a fairly rigorous approach, gold-nanocoated dielectric optical fibers are treated to evaluate the propagation characteristics corresponding to the transverse electric (TE) and hybrid EH modes, as supported by the guides with small and large dimensions. Situations with varying nanocoating thickness are considered for two different operating wavelengths. The results demonstrate a profound effect of the gold nanocoating on the propagation-related features—the number of existing modes decreases with increasing nanolayer thickness. Furthermore, the gold nanolayer also has effects on the modal propagation constants, which become more prominent with the increase in the order of modes. It has been found that, in fiber with smaller dimension, the EH11mode hardly exhibits any effect due to the variation in existing nanolayer coating corresponding to 850 nm wavelength. Almost similar situations are observed for the TE01mode in large core fiber operating at 1550 nm wavelength.

Gli stili APA, Harvard, Vancouver, ISO e altri

45

Angelini, Alessandro. "A Favela That Yields Fruit: Community-Based Tour Guides as Brokers in the Political Economy of Cultural Difference". Space and Culture 23, n. 1 (2 agosto 2019): 15–33. http://dx.doi.org/10.1177/1206331219865694.

Testo completo

Abstract (sommario):

Reversing decades of fear and neglect as no-go zones for outsiders, Rio de Janeiro’s most iconic favela communities have become tourist attractions offering a glimpse of the purported “other side” of Brazilian society as well as panoramic vistas over the Marvelous City. Since 2010, tourism has become a vehicle and justification for security, infrastructure, and capacity-building projects in Rio’s favelas. Promoted as an exemplary favela in this social uplift scheme, Santa Marta has received thousands of tourists per year. In an unprecedented step, Santa Marta guides organized themselves into a committee to collectively manage the tourism enterprise and to promote themselves as a brand of community-based tourism in contradistinction to outside commercial tour operators. Their authority and authenticity as local experts hinge on the emergent perception of the favela itself as a resource and that their labor makes that value economically productive. This article analyzes the work of these guides as cultural brokers to think through the semiotically overdetermined yet shifting status of the favela as space of cultural alterity from the perspective of those who are both targets and agents of its transformation. Exploring how community-based guides have emerged as political and economic brokers, this article suggests that their performances as local experts, as well as their modes of organizing, shape tensions and contradictions of the favela as a commodified place. It demonstrates how collectivist and competitive interests among guides embody differing perspectives on state intervention in their community. The discussions and conflicts among tour guides themselves embody the tensions over the future of communities long marginalized by state and capital yet suddenly targeted for economic investment and cultural valorization.

Gli stili APA, Harvard, Vancouver, ISO e altri

46

Madine, K. H., e D. J. Colquitt. "Dynamic Green’s functions in discrete flexural systems". Quarterly Journal of Mechanics and Applied Mathematics 74, n. 3 (1 agosto 2021): 323–50. http://dx.doi.org/10.1093/qjmam/hbab006.

Testo completo

Abstract (sommario):

Summary The article presents an analysis of the dynamic behaviour of discrete flexural systems composed of Euler–Bernoulli beams. The canonical object of study is the discrete Green’s function, from which information regarding the dynamic response of the lattice under point loading by forces and moments can be obtained. Special attention is devoted to the interaction between flexural and torsional waves in a square lattice of Euler–Bernoulli beams, which is shown to yield a range of novel effects, including extreme dynamic anisotropy, asymmetric wave propagation, wave-guiding, filtering and the ability to create localised defect modes, all without the need for additional resonant elements or interfaces. The analytical study is complimented by numerical computations and finite element simulations, both of which are used to illustrate the effects predicted. A general algorithm is provided for constructing Green’s functions as well as defect modes. This algorithm allows the tuning of the lattice to produce pass bands, band gaps, resonant modes, wave-guides and defect modes, over any desired frequency range.

Gli stili APA, Harvard, Vancouver, ISO e altri

47

Lamouche, Guy, e S. Iraj Najafi. "Scalar finite-element evaluation of cut-off wavelength in glass wave guides and comparison with experiment". Canadian Journal of Physics 68, n. 11 (1 novembre 1990): 1251–56. http://dx.doi.org/10.1139/p90-180.

Testo completo

Abstract (sommario):

The scalar finite-element method is used to analyze ion-exchanged glass channel waveguides. Cut-off wavelengths for fundamental and first-order modes are calculated and the single-mode region is determined. The results are compared with the experimentally measured values.

Gli stili APA, Harvard, Vancouver, ISO e altri

48

Wang, Ya Yun, Yan An Zhang, Jin Wu Qian e Lin Yong Shen. "Accuracy Analysis of Focusing Mechanism for an ICF Facility". Applied Mechanics and Materials 703 (dicembre 2014): 203–10. http://dx.doi.org/10.4028/www.scientific.net/amm.703.203.

Testo completo

Abstract (sommario):

The focusing Mechanism is an important component of Final Optic Assembly (FOA) in an ICF facility. In this paper, focusing mechanism structure and factors that influence its targeting accuracy were discussed. The impact of the lens pose on targeting when four cylindrical guides were distributed in 4×90°is studied. And it was compared with the situation when three cylindrical guides distributed in isosceles triangle were used. The geometric model was built to analyze the target error caused by the deformation of the front and rear flat. In the end, the deformation was calculated by ANSYS. The result shows that the deviation change is minimized when the diameters of the support rods and guides take specific value.

Gli stili APA, Harvard, Vancouver, ISO e altri

49

Fu, Jinlan, Pengfei Liu e Qi Zhang. "Rethinking Generalization of Neural Models: A Named Entity Recognition Case Study". Proceedings of the AAAI Conference on Artificial Intelligence 34, n. 05 (3 aprile 2020): 7732–39. http://dx.doi.org/10.1609/aaai.v34i05.6276.

Testo completo

Abstract (sommario):

While neural network-based models have achieved impressive performance on a large body of NLP tasks, the generalization behavior of different models remains poorly understood: Does this excellent performance imply a perfect generalization model, or are there still some limitations? In this paper, we take the NER task as a testbed to analyze the generalization behavior of existing models from different perspectives and characterize the differences of their generalization abilities through the lens of our proposed measures, which guides us to better design models and training methods. Experiments with in-depth analyses diagnose the bottleneck of existing neural NER models in terms of breakdown performance analysis, annotation errors, dataset bias, and category relationships, which suggest directions for improvement. We have released the datasets: (ReCoNLL, PLONER) for the future research at our project page: http://pfliu.com/InterpretNER/.

Gli stili APA, Harvard, Vancouver, ISO e altri

50

Kartik, V., e J. A. Wickert. "Surface Friction Guiding for Reduced High-Frequency Lateral Vibration of Moving Media". Journal of Vibration and Acoustics 129, n. 3 (25 ottobre 2006): 371–79. http://dx.doi.org/10.1115/1.2732354.

Testo completo

Abstract (sommario):

The free and forced vibration of a moving medium is examined in an application where distributed friction guiding is used to control lateral position passively. Subambient pressure features formed in the guides intentionally modify the naturally occurring self-pressurized air bearing and increase the contact force between the medium and the guide’s surface. These features increase friction to a level beyond that achievable based on the nominal wrap pressure. The moving medium is modeled as a beam that is transported over frictional regions and subjected to prescribed boundary disturbances arising from runout of a supply or take-up roll. For axial transport at a speed that is high compared to the velocity of lateral vibration, Coulomb friction between the guides and the moving medium can be well approximated by a derived expression for equivalent viscous damping. The equation of motion is developed for the cases of a single cylindrical guide and of a multiplicity of guides having arbitrary placement. The level of equivalent damping for each mode decreases with transport speed, and critical speeds exist where each vibration mode transitions between the overdamped and underdamped regimes. Parameter studies in the contact pressure, transport speed, and guide geometry identify preferred design configurations for maximizing dissipation in particular modes and for attenuating high-frequency response.

Gli stili APA, Harvard, Vancouver, ISO e altri

Articoli di riviste sul tema "Guides à modes lents"

Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili