Academic literature on the topic 'Focal Depths'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Focal Depths.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Focal Depths":
1
Yun, Sukyoung, Won Sang Lee, Robert P. Dziak, and Haruyoshi Matsumoto. "Numerical Study on the Characteristics of Abyssal T-Wave Envelopes Controlled by Earthquake Source Parameters." Seismological Research Letters 93, no. 4 (April 19, 2022): 2189–200. http://dx.doi.org/10.1785/0220210264.
Abstract:
Abstract Hydroacoustics has been successfully applied to detect and locate small-to-intermediate submarine tectonic activities infrequently recorded in land-based seismic arrays. However, to extend the utilization of T waves to extract other important earthquake source parameters, such as source strength, the roles of earthquake focal mechanisms, and source depths in T-wave envelopes must be thoroughly understood. We performed 3D numerical modeling considering anisotropic source radiation and realistic scattering in the oceanic crust for two focal mechanisms (normal and strike-slip faults) and three depths (5, 10, and 15 km) to investigate the effect of source radiation and focal depth on abyssal T waves. By analyzing the synthetic T-wave envelopes, we showed that stronger SV-energy radiation from a normal-fault earthquake event generates higher-intensity T waves of the same source magnitude. The anisotropic source radiation of a double-couple source causes azimuthal changes in the shapes of T waves, and deeper earthquakes cause gentle-sloped envelopes; however, the slopes also vary with respect to the azimuths of receivers and focal mechanisms. Temporal changes in the slopes of T-wave envelopes of magmatic swarm events near Wordie Volcano, Bransfield Strait, Antarctic Peninsula, imply that the depth dependency can be utilized to determine relative depths for hydrothermal-vent events or sequenced earthquakes.
2
Szeidovitz, Gy, Z. Bus, and K. Gribovszki. "Focal depths of earthquakes in the Carpathian Basin." Acta Geodaetica et Geophysica Hungarica 39, no. 4 (November 2004): 447–70. http://dx.doi.org/10.1556/ageod.39.2004.4.13.
3
Wang, Yaheng, Li Yi, Masayoshi Tonouchi, and Tadao Nagatsuma. "High-Speed 600 GHz-Band Terahertz Imaging Scanner System with Enhanced Focal Depth." Photonics 9, no. 12 (November 28, 2022): 913. http://dx.doi.org/10.3390/photonics9120913.
Abstract:
Lenses/mirrors with fast data acquisition speeds and extended focal depths have practical importance in terahertz (THz) imaging systems. Thus, a high-speed 600 GHz-band THz imaging scanner system with enhanced focal depth is presented in this work. A polygon mirror with a 250 Hz scanning frequency and an integrated off-axis parabolic (OAP) mirror with an ~170 mm focal depth were employed for 2D imaging. The simulation and experimental results show that a spatial resolution of ~2 mm can be achieved as the imaging distance varies from ~85 to 255 mm. The proposed system was applied to image a hidden metal object as a potential security application, demonstrating that this system can image targets with an enhanced focal depth.
4
Palmeri, Mark L., Kristin D. Frinkley, Katherine G. Oldenburg, and Kathryn R. Nightingale. "Characterizing Acoustic Attenuation of Homogeneous Media Using Focused Impulsive Acoustic Radiation Force." Ultrasonic Imaging 28, no. 2 (April 2006): 114–28. http://dx.doi.org/10.1177/016173460602800204.
Abstract:
A new method to characterize a material's attenuation using acoustic radiation force is proposed. Comparison of displacement magnitudes generated in a homogeneous material by acoustic radiation force excitations can be used to estimate the material's attenuation when the excitations are applied over a range of focal depths while maintaining a constant lateral focal configuration. Acoustic attenuations are related to the inverse of the excitation focal depth that yields the greatest focal zone displacement for this protocol. Experimental studies in calibrated tissue-mimicking phantoms are presented to demonstrate the feasibility of this method. Attenuations ranging from 0.3–1.5 dB/cm/MHz were characterized over excitation focal depths ranging from 5–30 mm, with an accuracy of 0.1 ± 0.15 dB/cm/MHz. As currently implemented, this method is limited to characterizing materials that have homogeneous material properties and acoustic attenuations. This method for characterizing acoustic attenuation can be performed using conventional diagnostic scanners without any additional hardware and could also be performed concurrently with acoustic radiation force-based imaging modalities to generate images of mechanical properties and attenuation that are spatially co-registered with B-mode images.
5
Nguyen, Thanh Phuoc, Van Tu Nguyen, Sudip Mondal, Van Hiep Pham, Dinh Dat Vu, Byung-Gak Kim, and Junghwan Oh. "Improved Depth-of-Field Photoacoustic Microscopy with a Multifocal Point Transducer for Biomedical Imaging." Sensors 20, no. 7 (April 3, 2020): 2020. http://dx.doi.org/10.3390/s20072020.
Abstract:
In this study, a photoacoustic microscopy (PAM) system based on a multifocal point (MFP) transducer was fabricated to produce a large depth-of-field tissue image. The customized MFP transducer has seven focal points, distributed along with the transducer’s axis, fabricated by separate spherically-focused surfaces. These surfaces generate distinct focal zones that are overlapped to extend the depth-of-field. This design allows extending the focal zone of 10 mm for the 11 MHz MFP transducer, which is a great improvement over the 0.48 mm focal zone of the 11 MHz single focal point (SFP) transducer. The PAM image penetration depths of a chicken-hemoglobin phantom using SFP and MFP transducers were measured as 5 mm and 8 mm, respectively. The significant increase in the PAM image-based penetration depth of the chicken-hemoglobin phantom was a result of using the customized MFP transducer.
6
Ma, Shutian, and Dariush Motazedian. "Focal depth distribution of the 1982 Miramichi earthquake sequence determined by modelling depth phases." Canadian Journal of Earth Sciences 54, no. 4 (April 2017): 359–69. http://dx.doi.org/10.1139/cjes-2016-0111.
Abstract:
On 9 January 1982, in the Miramichi region of New Brunswick, Canada, an earthquake with body-wave magnitude (mb) 5.7 occurred, and extensive aftershocks followed. The mainshock was felt throughout Eastern Canada and New England, USA. The mainshock and several principal aftershocks were digitally recorded worldwide, but smaller aftershocks were digitally recorded only at regional stations. Digital stations were not yet popular in 1982; therefore, available regional digital waveform records for modelling are very limited. Fortunately, two Eastern Canada Telemetered Network (ECTN) stations, EBN and KLN, produced excellent waveform records for most of the aftershocks until their closure at the end of 1990. The waveform records can be retrieved from the archive database at the Geological Survey of Canada (GSC). Since EBN had clear sPmP records of the larger aftershocks (with magnitude mN ≥ 2.8), we were able to determine focal depths for these larger events. Most of the focal depth solutions for the 113 larger aftershocks were within a depth range of 3–6 km. The majority of the depths were at about 4.5 km. Some aftershocks had depths of about 1–2 km. The focal depth solutions for the shallow events were confirmed by the existence of prominent crustal Rayleigh waves. As the records for the foreshock and the mainshock at EBN were not available, we used the records at station LMN for the foreshock and a teleseismic depth phase for the mainshock. The teleseismic depth phase comparison shows that the mainshock and its three principal aftershocks migrated from a depth of about 7 km to near the Earth’s surface.
7
Li, Chuan, Wenqi Gao, Youxue Wang, and Songping Yu. "Accurate Redetermination of the Focal Depth by Using the Time Intervals between the Inner Core Phases PKIKP and pPKIKP." Applied Sciences 12, no. 15 (July 29, 2022): 7669. http://dx.doi.org/10.3390/app12157669.
Abstract:
The hypocenter parameters of an earthquake may give us an insight into the Earth’s structure and tectonic processes. Among the hypocenter parameters, the focal depth is normally more difficult to estimate than the earthquake location (latitude and longitude). We propose to use the pPKIKP-PKIKP arrival time intervals for estimating the focal depth. We analyze the sensitivity of the pPKIKP-PKIKP arrival time interval to the earthquake depth. We measure the pPKIKP-PKIKP arrival time interval on seismograms (the vertical component), and invert the time interval data set using the simulated annealing inversion algorithm. We illustrate the inversion approach on two teleseismic earthquakes which have shallow and deep focal depths, and demonstrate that the approach is indeed appropriate to the shallow and deep event. We can obtain a reliable estimate on focal depth, even though the seismic station is sparse or in a remote part of the epicenter.
8
González-Salido, Nuria, and Jorge Camacho. "Normalization of Multifocal Acoustic Radiation Force Impulse Images." Archives of Acoustics 42, no. 2 (June 27, 2017): 321–31. http://dx.doi.org/10.1515/aoa-2017-0034.
Abstract:
Abstract Imaging the tissue displacements caused by Acoustic Radiation Force Impulse (ARFI) provides qualitative tissue elasticity maps around the focus. To increase imaging range, multi-focus techniques combine several images obtained with different focal depths. Since the acoustic radiation force depends on focus depth, axial distance and steering angle, a normalization process is required before blending multi-focal ARFI images so that changes in the displayed displacements represent true tissue elasticity variations. This work analyzes the sources of displacement variability in multi-focal-zone ARFI and proposes a procedure to normalize and combine partial images. The proposal is based on the system focal configuration, transducer characteristics and global tissue parameters found by ultrasonic measurements. Performance of the proposed algorithm is experimentally evaluated with tissue mimicking phantoms.
9
Plourde, Alexandre P., and Mladen R. Nedimović. "Earthquake Depths, Focal Mechanisms, and Stress in the Lower St. Lawrence Seismic Zone." Seismological Research Letters 92, no. 4 (May 5, 2021): 2562–72. http://dx.doi.org/10.1785/0220200429.
Abstract:
Abstract We examine earthquake hypocenters, focal mechanisms, and the state of tectonic stress in the Lower St. Lawrence Seismic Zone (LSZ), a paleorift zone in eastern Canada. The largest earthquake recorded in the region is the 1999 Côte–Nord MN 5.1, which was followed by ∼80 aftershocks of MN>1. It is not known if the region is capable of producing hazardous Mw>6 earthquakes, similar to the Charlevoix Seismic Zone ∼250 km upriver. Focusing on 2015–2020, we apply a machine-learning-based phase picker to detect 72 earthquakes in addition to the 150 catalog earthquakes in the same region over this time span. We produce an updated 1D, gradient velocity model via a Monte Carlo search using a uniform VP/VS=1.77, which we computed with the Wadati method. We refine hypocenter estimates using the triple-difference method, with sP depth phases as additional constraints on earthquake depth. We estimate focal mechanisms for >100 earthquakes with automatically picked P-wave first motions and absolute value P-SV-SH amplitude ratios, and we use the focal mechanisms to invert for the state of tectonic stress. Grid searches and Bayesian analysis allow for robust uncertainty estimates of focal mechanisms, which in turn allow for uncertainty estimates of the stress tensor. The recovered west-northwest–east-southeast σ1 is consistent with previous estimates and with a stress tensor controlled by glacial isostatic adjustment, although a contrast between deep and shallow focal mechanisms suggests that these stresses may be concentrated in the lower crust. Epicenter lineations up to ∼40 km long may be indicative of sizable faults in the LSZ capable of generating Mw>6 earthquakes, but hypocenter and focal mechanism uncertainties are too high to say so definitively, thus pointing to a need for denser station coverage, including ocean-bottom seismometers.
10
Kulchitsky, V. E., B. G. Pustovitenko, and V. A. Svidlova. "Focal Depths of Earthquakes in the Crimea–Black Sea Region." Seismic Instruments 54, no. 3 (May 2018): 340–61. http://dx.doi.org/10.3103/s0747923918030155.
Dissertations / Theses on the topic "Focal Depths":
1
Huang, Paul Yi-Fa. "Focal depths and mechanisms of mid-ocean ridge earthquakes from body waveform inversion." Thesis, Massachusetts Institute of Technology, 1985. http://hdl.handle.net/1721.1/54310.
Abstract:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1986.Microfiche copy available in Archives and Science
Bibliography: leaves 230-249.
by Paul Yi-Fa Huang.
Ph.D.
2
Dahal, Nawa. "Improving the determination of moment tensors, moment magnitudes and focal depths of earthquakes below Mw 4.0 using regional broadband seismic data:." Thesis, Boston College, 2019. http://hdl.handle.net/2345/bc-ir:108624.
Abstract:
Thesis advisor: Michael J. NaughtonThesis advisor: John E. Ebel
Determining accurate source parameters of small magnitude earthquakes is important to understand the source physics and tectonic processes that activate a seismic source as well as to make more accurate estimates of the probabilities of the recurrences of large earthquakes based on the statistics of smaller earthquakes. The accurate determination of the focal depths and focal mechanisms of small earthquakes is required to constrain the potential seismic source zones of future large earthquakes, whereas the accurate determination of seismic moment is required to calculate the sizes (best represented by moment magnitudes) of earthquakes. The precise determination of focal depths, moment magnitudes and focal mechanisms of small earthquakes can help greatly advance our knowledge of the potentially active faults in an area and thus help to produce accurate seismic hazard and risk maps for that area. Focal depths, moment magnitudes and focal mechanisms of earthquakes with magnitudes Mw 4.0 and less recorded by a sparse seismic network are usually poorly constrained due to the lack of an appropriate method applicable to find these parameters with a sparse set of observations. This dissertation presents a new method that can accurately determine focal depths, moment magnitudes and focal mechanisms of earthquakes with magnitudes between Mw 4.0 and Mw 2.5 using the broadband seismic waveforms recorded by the local and regional seismic stations. For the determination of the focal depths and the moment magnitudes, the observed seismograms as well as synthetic seismograms are filtered through a bandpass filter of 1-3 Hz, whereas for the determination of the focal mechanisms, they are filtered through a bandpass filter of 1.5-2.5 Hz. Both of these frequency passbands have a good signal-to-noise ratio (SNR) for the small earthquakes of the magnitudes that are analyzed in this dissertation. The waveforms are processed to their envelopes in order to make the waveforms relatively simple for the modeling. A grid search is performed over all possible dip, rake and strike angles and as well as over possible depths and scalar moments to find the optimal value of the focal depth and the optimal value of the scalar moment. To find the optimal focal mechanism, a non-linear moment-tensor inversion is performed in addition to the coarse grid search over the possible dip, rake and strike angles at a fixed value of focal depth and a fixed value of scalar moment. The method of this dissertation is tested on 18 aftershocks of Mw between 3.70 and 2.60 of the 2011 Mineral, Virginia Mw 5.7 earthquake. The method is also tested on 5 aftershocks of Mw between 3.62 and 2.63 of the 2013 Ladysmith, Quebec Mw 4.5 earthquake. Reliable focal depths and moment magnitudes are obtained for all of these events using waveforms from as few as 1 seismic station within the epicentral distance of 68-424 km with SNR greater or equal to 5. Similarly, reliable focal mechanisms are obtained for all of the events with Mw 3.70-3.04 using waveforms from at least 3 seismic stations within the epicentral distance of 60-350 km each with SNR greater or equal to 10. Tests show that the moment magnitudes and focal depths are not very sensitive to the crustal model used, although systematic variations in the focal depths are observed with the total crustal thickness. Tests also show that the focal mechanisms obtained with the different crustal structures vary with the Kagan angle of 30o on average for the events and the crustal structures tested. This means that the event moment magnitudes and event focal mechanism determinations are only somewhat sensitive to the uncertainties in the crustal models tested. The method is applied to some aftershocks of the Mw 7.8, 2015 Gorkha, Nepal earthquake which shows that the method developed in this dissertation, by analyzing data from eastern North America, appears to give good results when applied in a very different tectonic environment in a different part of the world. This study confirms that the method of modeling envelopes of seismic waveforms developed in this dissertation can be used to extract accurate focal depths and moment magnitudes of earthquakes with Mw 3.70-2.60 using broadband seismic data recorded by local and regional seismic stations at epicentral distances of 68-424 km and accurate focal mechanisms of earthquakes with Mw 3.70-3.04 using broadband seismic data recorded by local and regional seismic stations at epicentral distances of 60-350 km
Thesis (PhD) — Boston College, 2019
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Physics
3
Laporte, Marine. "Contribution à l'amélioration de l’estimation de la profondeur hypocentrale à partir de réseaux régionaux ou globaux." Electronic Thesis or Diss., Université Paris sciences et lettres, 2022. http://www.theses.fr/2022UPSLE055.
Abstract:
Cette thèse s’intéresse aux différentes méthodes d’estimation de la profondeur hypocentrale ainsi qu’à la mise en évidence des incertitudes de localisation qui peuvent leur être associées. À distance régionale, on utilise ces méthodes pour cartographier les petites variations de profondeur hypocentrales liées à l’activité du grand chevauchement himalayen au Népal ou pour analyser des crises sismiques choisies selon l’actualité et les opportunités rencontrées durant ces trois ans de thèse. Les effets des différentes sources d’incertitudes sur l’estimation de la profondeur hypocentrale sont quantifiés par le biais d’une analyse de sensibilité globale de type Sobol-Monte Carlo. Pour améliorer l’estimation de la profondeur hypocentrale à distance télésismique, on développe une nouvelle méthode d’estimation de la profondeur à partir des arrivées pP/sP dans les enveloppes énergétiques des signaux. Une adaptation de cette méthode permet notamment de mettre en évidence des variations latérales relatives de profondeur le long d’interfaces de subduction au Chili et en Équateur. Les différentes échelles d’observations et les différentes techniques d’estimation de la profondeur sont confrontées sur des ensembles d’évènements de magnitude intermédiaire (M>5) afin de caractériser l’incertitude de profondeur à distance télésismique, mettre en évidence ou quantifier des sources de biais spécifiques ou pour renforcer certaines interprétations sismotectoniques régionalesThis thesis focuses on the different methods of estimating hypocentral depth and on the identification of localization uncertainties that may be associated with them. At a regional distance, we use these methods to map small hypocentral depth variations related to the activity of the Great Himalayan Thrust in Nepal or to analyze opportunistic seismic crisis. The effects of different sources of uncertainty on the hypocentral depths are quantified through a global Sobol-Monte Carlo sensitivity analysis. To improve the estimation of the hypocentral depth at teleseismic distance, we develop a new method of depth identification from the pP/sP arrivals in the energetic envelopes of the teleseismic signals. An adaptation of this teleseismic envelopes method allows us to highlight relative lateral depth variations along subduction interfaces in Chile and Ecuador. The different scales of observations and the different depth estimation techniques are compared on intermediate magnitude events (M>5) in order to characterize the depth uncertainty at teleseismic distance, to highlight or quantify specific sources of bias or to reinforce some regional seismotectonic interpretations
4
Hu, Xinda. "Development Of The Depth-Fused Multi-Focal-Plane Display Technology." Diss., The University of Arizona, 2014. http://hdl.handle.net/10150/338957.
Abstract:
Conventional stereoscopic displays present a pair of stereoscopic images on a single and fixed image plane. In consequence, these displays lack the capability of correctly rendering focus cues (i.e. accommodation and retinal blur) and may induce the discrepancy between accommodation and convergence. A number of visual artifacts associated with incorrect focus cues in stereoscopic displays have been reported, limiting the applicability of these displays for demanding applications and daily usage. Depth-fused multi-focal-plane display was proposed to create a fixed-viewpoint volumetric display capable of rendering correct or nearly-correct focus cues in a stereoscopic display through a small number of discretely placed focal planes. It effectively addresses the negative effects of conventional stereoscopic displays on depth perception accuracy and visual fatigue. In this dissertation, the fundamental design methods and considerations of depth-fused displays were refined and extended based on previous works and a high-resolution optical see-through multi-focal-plane head-mounted display enabled by state-of-the-art freeform optics was developed. The prototype system is capable of rendering nearly-correct focus cues for a large volume of 3D space extending into a depth range from 0 to 3 diopters at flicker-free speed. By incorporating freeform optics, the prototype not only achieves high quality imagery across a large 3D volume for the virtual display path but it also maintains better than 0.5 arcminutes visual resolution of the see-through view. The optical design, implementation and experimental validation of the display are presented and discussed in detail.
5
Massey, Kristen L. "Procedural Calibration of Haploscope Wings to Establish Accurate Focal Vergence Depth." Thesis, Mississippi State University, 2019. http://pqdtopen.proquest.com/#viewpdf?dispub=10980275.
Abstract:
This thesis project was undertaken with the intent to discover the source of a known but hitherto unexplained error in the calibration of the wings for a haploscope used in depth perception studies.
The angles of the haploscope wings are used to control the vergence angle of the virtual images projected into each eye. This accounts for a strong depth cue used in AR and depth perception studies. Two experiments were devised to both display and attempt to characterize the error between the theoretical wing angles needed to cause a user’s vision to verge at some focal depth and the actual wing angles that caused vergence. The investigation revealed a near-constant offset between the theoretical and actual angles needed. This suggests that the error may not stem from the haploscope alignment itself, but from how the center of the user’s eye is currently modeled.
6
Gupta, Divya. "An Empirical Study of the Effects of Context-Switch, Object Distance, and Focus Depth on Human Performance in Augmented Reality." Thesis, Virginia Tech, 2004. http://hdl.handle.net/10919/33507.
Abstract:
Augmented reality provides its user with additional information not available through the natural real-world environment. This additional information displayed to the user potentially poses a risk of perceptual and cognitive load and vision-based difficulties. The presence of real-world objects together with virtual augmenting information requires the user to repeatedly switch eye focus between the two in order to extract information from both environments. Switching eye focus may result in additional time on user tasks and lower task accuracy. Thus, one of the goals of this research was to understand the impact of switching eye focus between real-world and virtual information on user task performance. Secondly, focus depth, which is an important parameter and a depth cue, may affect the userâ s view of the augmented world. If focus depth is not adjusted properly, it may result in vision-based difficulties and reduce speed, accuracy, and comfort while using an augmented reality display. Thus, the second goal of this thesis was to study the effect of focus depth on task performance in augmented reality systems.
In augmented reality environments, real-world and virtual information are found at different distances from the user. To focus at different depths, the userâ s eye needs to accommodate and converge, which may strain the eye and degrade performance on tasks. However, no research in augmented reality has explored this issue. Hence, the third goal of this thesis was to determine if distance of virtual information from the user impacts task performance.
To accomplish these goals, a 3x3x3 within subjects design was used. The experimental task for the study required the user to repeatedly switch eye focus between the virtual text and real-world text. A monocular see-through head- mounted display was used for this research.
Results of this study revealed that switching between real-world and virtual information in augmented reality is extremely difficult when information is displayed at optical infinity. Virtual information displayed at optical infinity may be unsuitable for tasks of the nature used in this research. There was no impact of focus depth on user task performance and hence it is preliminarily recommended that manufacturers of head-mounted displays may only need to make fixed focus depth displays; this clearly merits additional intensive research. Further, user task performance was better when focus depth, virtual information, and real-world information were all at the same distance from the user as compared to conditions when they were mismatched. Based on this result we recommend presenting virtual information at the same distance as real-world information of interest.
Master of Science
7
Paerhati, Paruku. "Real-time monocular depth mapping system using variance of focal plane and pixel focus measure." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/113117.
Abstract:
Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2017.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (page 48).
Vision is one of the most powerful senses available to creatures. Undoubtedly, many of the fundamental operations of humans, such as the ability to plan paths, avoid obstacles, and recognize objects, depend heavily on their visual perception of the world around them. Although humans have naturally evolved to efficiently use their stereo optical prowess to develop an understanding of their environment, artificial machines and systems in comparison have just begun to utilize computer vision to create awareness of local physical entities. One of the most important sensory skills creatures have is depth perception, which allows them to estimate the relative distance of objects in their vision from many visual cues. Many systems have been developed to aid machines in perceiving the depth map of their environment, and each system has its drawbacks and benefits. In this paper, we introduce the design and implementation of a new system which provides a depth map from the use of a single optical camera with focal plane variation in the images taken. The paper focuses on the methods used to scale the depth from focus algorithm to perform in real-time. The results also showcase a real-time depth mapping system capable of providing rich depth maps of scenes at a high framerate and with advanced noise filtration techniques.
by Paruku Paerhati.
M. Eng.
8
Rodriguez, Joaquin. "Calibration and 3D vision with a color-polarimetric camera." Electronic Thesis or Diss., Bourgogne Franche-Comté, 2023. http://www.theses.fr/2023UBFCK062.
Abstract:
Parmi les différentes modalités employées en détection, les capteurs de vision sont ceux qui fournissent le plus d'informations sur l'environnement. L'utilisation d'objectifs à courte focale permet en outre d'augmenter facilement la zone observée. L'apparition sur le marché d'imageurs couleurs et polarimétriques permet d'étendre encore davantage les applications en estimation de profondeur. En effet, les paramètres de polarisation de la lumière réfléchies ont liés à la nature des objets ainsi qu'à leur géométrie et peuvent être utilisés avantageusement. Dans cette thèse, notre objectif principal est d'étudier l'utilisation des données de polarisation pour améliorer les capacités de perception appliquées aux tâches robotiques, notamment dans la reconstruction de la profondeur de scène. De plus, nous visons à enrichir les connaissances dans le domaine de l'imagerie de polarisation en fournissant à d'autres chercheurs un ensemble d'outils qui leur permettront d'accéder rapidement à la modalité de polarisation. Après avoir effectué une introduction complète à la théorie et à la modélisation de la polarisation, nous décrivons comment calibrer un capteur de polarisation de division de plan focale. Ce dispositif de détection permet de capturer deux modalités (couleur et polarisation) avec une seule prise de vue. La nouvelle technique de calibration que nous proposons permet à ce dispositif de fournir des mesures plus précises en ajustant un modèle mathématique selon chaque pixel. La méthode que nous présentons ici vise à réduire la quantité d'équipement, donc le temps expérimental nécessaire pour obtenir des mesures calibrées. Nous détaillons également toute la physique sous-jacente à la technique de Shape-from-polarization (SfP) qui permet d'estimer le champ des normales d'un objet en utilisant l'information de la polarisation. Les équations nécessaires et les modèles inverses pour dériver les paramètres des vecteurs depuis l'état de polarisation sont détaillées tout en tenant compte du type de réflexion et du matériau. Nous mettons ici en avant l'intérêt de notre algorithme de calibrage sur l'estimation du champ de normales par polarisation L'estimation d'informations de profondeur grâce à l'intelligence artificielle a connu un essort très important ces dernières années. Dans ce contexte, nous proposons également un réseau d'apprentissage profond pour estimer la profondeur basé sur une architecture de fusion intermédiaire et une fonction de perte polarimétrique. L'objectif de ce développement est de montrer comment intégrer efficacement les contraintes de la théorie de la polarisation dans un algorithme basé sur les données. Une évaluation qualitative et quantitative des résultats démontrent l'intérêt de l'utilisation d'un imageur RGB-polarimétrique grâce à l'apport des informations de polarisation. Lors de ces travaux de recherche, une boîte à outils logiciel scomplète a également été développée proposant ainsi à la communauté scientifique un logiciel d'accès simplifié à l'imagerie polarimétriqueAmong the different sensing modalities, vision sensors are the ones thatprovide the most abundant environmental information. Additionally, the usage ofa short focal length lens allows to easily increase the observed area. The releaseof color and polarimetric imagers makes it possible to extend even more thepolarimetric application related to depth estimation. Indeed, the polarizationparameters of the reflected light are related to the nature and to the geometryof the objects, which can be used advantageously. In this thesis, our mainobjective is to study the usage of polarization data to enhance theperception capabilities applied to robotics tasks, particularly in the task ofscene depth reconstruction. Furthermore, we aim to push the knowledge in thefield of polarization imaging by providing other researchers with a set of toolsthat will allow them to quickly access the polarization modality. After doing acomplete introduction to the polarization theory and modeling, we describe howto calibrate a DoFP sensor. This sensing device allows to capture twomodalities (color and polarization) with a single snapshot. The new calibrationtechnique that we propose enables this device to provide more accuratemeasurements by fitting a mathematical model to each individual pixel. Themethod we present here aims to reduce the amount of equipment and, thus theexperimental time required to obtain calibrated measurements. We make a detailedexplanation of the physics underlying the Shape-from-Polarization technique, which enablesthe normal field estimation of an object by using polarization cues. All therequired equations as well as their inverted versions for deriving the vectorparameters from the polarization state are detailed while taking intoconsideration the type of reflection and material. We also put in evidence theeffects of our calibration algorithm over the estimation of the normal vectorfield by using polarization. The estimation of depth information usingartificial intelligence has seen significant growth in recent years. In thiscontext, we also propose a deep-learning network to estimate depth based on amiddle-fusion architecture, and a polarimetric loss function. The objective ofthis development is to show how to effectively integrate the polarization theoryconstraints into a data-driven algorithm. A qualitative and quantitativeevaluation of the results shows the interest of using an RGB-polarimetric imagerthanks to the contribution of the polarization information. During this researchwork, a complete software toolbox was also developed, providing the scientificcommunity with simplified access to polarimetric imaging
9
Kosmata, Marcel. "Elastische Rückstoßatomspektrometrie leichter Elemente mit Subnanometer-Tiefenauflösung." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-84041.
Abstract:
In der vorliegenden Arbeit wird erstmals das QQDS-Magnetspektrometer für die höchstauflösende Ionenstrahlanalytik leichter Elemente am Helmholtz-Zentrum Dresden-Rossendorf umfassend vorgestellt. Zusätzlich werden sowohl alle auf die Analytik Einfluss nehmenden Parameter untersucht als auch Methoden und Modelle vorgestellt, wie deren Einfluss vermieden oder rechnerisch kompensiert werden kann. Die Schwerpunkte dieser Arbeit gliedern sich in fünf Bereiche. Der Erste ist der Aufbau und die Inbetriebnahme des QQDS-Magnetspektrometers, der zugehörige Streukammer mit allen Peripheriegeräten und des eigens für die höchstauflösende elastische Rückstoßanalyse entwickelten Detektors. Sowohl das umgebaute Spektrometer als auch der im Rahmen dieser Arbeit gebaute Detektor wurden speziell an experimentelle Bedingungen für die höchstauflösende Ionenstrahlanalytik leichter Elemente angepasst und erstmalig auf einen routinemäßigen Einsatz hin getestet. Der Detektor besteht aus zwei Komponenten. Zum einen befindet sich am hinteren Ende des Detektors eine Bragg-Ionisationskammer, die zur Teilchenidentifikation genutzt wird. Zum anderen dient ein Proportionalzähler, der eine Hochwiderstandsanode besitzt und direkt hinter dem Eintrittsfenster montiert ist, zur Teilchenpositionsbestimmung im Detektor. Die folgenden zwei Schwerpunkte beinhalten grundlegende Untersuchungen zur Ionen-Festkörper-Wechselwirkung. Durch die Verwendung eines Magnetspektrometers ist die Messung der Ladungszustandsverteilung der herausgestreuten Teilchen direkt nach einem binären Stoß sowohl möglich als auch für die Analyse notwendig. Aus diesem Grund werden zum einen die Ladungszustände gemessen und zum anderen mit existierenden Modellen verglichen. Außerdem wird ein eigens entwickeltes Modell vorgestellt und erstmals im Rahmen dieser Arbeit angewendet, welches den ladungszustandsabhängigen Energieverlust bei der Tiefenprofilierung berücksichtigt. Es wird gezeigt, dass ohne die Anwendung dieses Modells die Tiefenprofile nicht mit den quantitativen Messungen mittels konventioneller Ionenstrahlanalytikmethoden und mit der Dickenmessung mittels Transmissionselektronenmikroskopie übereinstimmen, und damit falsche Werte liefern würden. Der zweite für die Thematik wesentliche Aspekt der Ionen-Festkörper-Wechselwirkung, sind die Probenschäden und -modifikationen, die während einer Schwerionen-bestrahlung auftreten. Dabei wird gezeigt, dass bei den hier verwendeten Energien sowohl elektronisches Sputtern als auch elektronisch verursachtes Grenzflächendurchmischen eintreten. Das elektronische Sputtern kann durch geeignete Strahlparameter für die meisten Proben ausreichend minimiert werden. Dagegen ist der Einfluss der Grenzflächendurchmischung meist signifikant, so dass dieser analysiert und in der Auswertung berücksichtigt werden muss. Schlussfolgernd aus diesen Untersuchungen ergibt sich für die höchstauflösende Ionenstrahlanalytik leichter Elemente am Rossendorfer 5-MV Tandembeschleuniger, dass die geeignetsten Primärionen Chlor mit einer Energie von 20 MeV sind. In Einzelfällen, wie zum Beispiel der Analyse von Bor, muss die Energie jedoch auf 6,5 MeV reduziert werden, um das elektronische Sputtern bei der notwendigen Fluenz unterhalb der Nachweisgrenze zu halten. Der vierte Schwerpunkt ist die Untersuchung von sowohl qualitativen als auch quantitativen Einflüssen bestimmter Probeneigenschaften, wie beispielsweise Oberflächenrauheit, auf die Form des gemessenen Energiespektrums beziehungsweise auf das analysierte Tiefenprofil. Die Kenntnis der Rauheit einer Probe an der Oberfläche und an den Grenzflächen ist für die Analytik unabdingbar. Als Resultat der genannten Betrachtungen werden die Einflüsse von Probeneigenschaften und Ionen-Festkörper-Wechselwirkungen auf die Energie- beziehungsweise Tiefenauflösung des Gesamtsystems beschrieben, berechnet und mit der konventionellen Ionenstrahlanalytik verglichen. Die Möglichkeiten der höchstauflösenden Ionenstrahlanalytik werden zudem mit den von anderen Gruppen veröffentlichten Komplementärmethoden gegenübergestellt. Der fünfte und letzte Schwerpunkt ist die Analytik leichter Elemente in ultradünnen Schichten unter Berücksichtigung aller in dieser Arbeit vorgestellten Modelle, wie die Reduzierung des Einflusses von Strahlschäden oder die Quantifizierung der Elemente im dynamischen Ladungszustandsnichtgleichgewicht. Es wird die Tiefenprofilierung von Mehrschichtsystemen, bestehend aus SiO2-Si3N4Ox-SiO2 auf Silizium, von Ultra-Shallow-Junction Bor-Implantationsprofilen und von ultradünnen Oxidschichten, wie zum Beispiel High-k-Materialien, demonstriertIn this thesis the QQDS magnetic spectrometer that is used for high resolution ion beam analysis (IBA) of light elements at the Helmholtz-Zentrum Dresden-Rossendorf is presented for the first time. In addition all parameters are investigated that influence the analysis. Methods and models are presented with which the effects can be minimised or calculated. There are five focal points of this thesis. The first point is the construction and commissioning of the QQDS magnetic spectrometer, the corresponding scattering chamber with all the peripherals and the detector, which is specially developed for high resolution elastic recoil detection. Both the reconstructed spectrometer and the detector were adapted to the specific experimental conditions needed for high-resolution Ion beam analysis of light elements and tested for routine practice. The detector consists of two compo-nents. At the back end of the detector a Bragg ionization chamber is mounted, which is used for the particle identification. At the front end, directly behind the entrance window a proportional counter is mounted. This proportional counter includes a high-resistance anode. Thus, the position of the particles is determined in the detector. The following two points concern fundamental studies of ion-solid interaction. By using a magnetic spectrometer the charge state distribution of the particles scattered from the sample after a binary collision is both possible and necessary for the analysis. For this reason the charge states are measured and compared with existing models. In addition, a model is developed that takes into account the charge state dependent energy loss. It is shown that without the application of this model the depth profiles do not correspond with the quantitative measurements by conventional IBA methods and with the thickness obtained by transmission electron microscopy. The second fundamental ion-solid interaction is the damage and the modification of the sample that occurs during heavy ion irradiation. It is shown that the used energies occur both electronic sputtering and electronically induced interface mixing. Electronic sputtering is minimised by using optimised beam parameters. For most samples the effect is below the detection limit for a fluence sufficient for the analysis. However, the influence of interface mixing is so strong that it has to be included in the analysis of the layers of the depth profiles. It is concluded from these studies that at the Rossendorf 5 MV tandem accelerator chlorine ions with an energy of 20 MeV deliver the best results. In some cases, such as the analysis of boron, the energy must be reduced to 6.5 MeV in order to retain the electronic sputtering below the detection limit. The fourth focus is the study of the influence of specific sample properties, such as surface roughness, on the shape of a measured energy spectra and respectively on the analysed depth profile. It is shown that knowledge of the roughness of a sample at the surface and at the interfaces for the analysis is needed. In addition, the contribution parameters limiting the depth resolution are calculated and compared with the conventional ion beam analysis. Finally, a comparison is made between the high-resolution ion beam analysis and complementary methods published by other research groups. The fifth and last focus is the analysis of light elements in ultra thin layers. All models presented in this thesis to reduce the influence of beam damage are taken into account. The dynamic non-equilibrium charge state is also included for the quantification of elements. Depth profiling of multilayer systems is demonstrated for systems consisting of SiO2-Si3N4Ox-SiO2 on silicon, boron implantation profiles for ultra shallow junctions and ultra thin oxide layers, such as used as high-k materials
10
Jing, Ruei-Ci Jhang, and 張簡瑞祈. "Bionic Compound Eye Microlens Array With Multifocus and Long Focal Depth." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/82428857462599080295.
Abstract:
碩士國立中興大學
精密工程學系所
104
This study aims to develop a bionic compound eye microlens array with multifocus and high depth of field to improve a selected vision quality. There are seven layers of microlens array designed in the bionic compound eye. These microlens array will focus on the same point composed a visual system. There are two parts in this study. The first part is the calculation of each layer''s microlens array focus on the same surfaces, Then the light path can be simulate using fabricated by the optic simulation software, ZEMAX. The second part is the bionic microlens array compound eye fabrication. The photoresist column array fabricated by lithography and followed by the thermal reflow can form the microlens array. A plastic replicate by elastic PDMS was used after sputtering. Then 3D printer was used to print the PDMS model which was hemisphere with some openings on the top, attached the replicated microlens array on the openings. The microlens array can from the curvature compound eye microlens array because of the negative pressure resulted in the hemisphere. A curvature with microlens array for the bionic compound eye, can be fabricated. The ZEMAX software can be used to simulate .
Books on the topic "Focal Depths":
1
Bollinger, G. A. Specification of source zones, recurrence rates, focal depths, and maximum magnitudes for earthquakes affecting the Savannah River site, in South Carolina. Washington, D.C: U.S. G.P.O., 1992.
2
Peterson, Bryan F. Understanding close-up photography: Creative close encounters with or without a macro Lens. New York: Amphoto Books, 2009.
3
Seeck, Margitta, and Donald L. Schomer. Intracranial EEG Monitoring. Edited by Donald L. Schomer and Fernando H. Lopes da Silva. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780190228484.003.0029.
Abstract:
Intracranial electroencephalography (iEEG) is used to localize the focus of seizures and determine vital adjacent cortex before epilepsy surgery. The two most commonly used electrode types are subdural and depth electrodes. Foramen ovale electrodes are less often used. Combinations of electrode types are possible. The choice depends on the presumed focus site. Careful planning is needed before implantation, taking into account the results of noninvasive studies. While subdural recordings allow better mapping of functional cortex, depth electrodes can reach deep structures. There are no guidelines on how to read ictal intracranial EEG recordings, but a focal onset (<5 contacts) and a high-frequency onset herald a good prognosis. High-frequency oscillations have been described as a potential biomarker of the seizure onset zone. Intracranial recordings provide a focal but magnified view of the brain, which is also exemplified by the use of microelectrodes, which allow the recording of single-unit or multi-unit activity.
4
Young, Emma. Masculinity. Edinburgh University Press, 2018. http://dx.doi.org/10.3366/edinburgh/9781474427739.003.0005.
Abstract:
Since the 1980s masculinity, more specifically ‘hegemonic masculinity’ has been a focal point of gender and sexuality discourses. The short story writings of Mantel, Hislop, and most particularly, Tremain, reflect, critique and problematize such understandings of masculinity. This chapter is shaped around three key areas that are often seen as defining masculinity: work, sexuality and the differences between male and female bodies. As with the historical strand of chapter three, in this chapter there will be a focus on history and one particularly significant historical moment for men and masculinity: the 1980s. It is through this analysis that questions will be addressed about how and why masculinity is a part of contemporary feminist discourses and, through the work of Judith Halberstam, will consider the ways in which queer theory and postmodern feminism have informed such debates. The momentary nature of the short story will be explored in greater depth too, in order to understand how the contemporary and historical moments interact in this narrative space.
5
Herron, Erik S., Robert J. Pekkanen, and Matthew S. Shugart, eds. The Oxford Handbook of Electoral Systems. Oxford University Press, 2017. http://dx.doi.org/10.1093/oxfordhb/9780190258658.001.0001.
Abstract:
No subject is more central to the study of politics than elections. All across the globe, elections are a focal point for citizens, the media, and politicians long before-and sometimes long after—they occur. Electoral systems, the rules about how voters’ preferences are translated into election results, profoundly shape not only the results of individual elections but also many other important political outcomes including party systems, candidate selection, and policy choices. Electoral systems have been a hot topic in established democracies from the United Kingdom and Italy to New Zealand and Japan. Even in the United States, events like the 2016 presidential election and court decisions such as Citizens United have sparked advocates to promote change in the Electoral College, redistricting, and campaign finance rules. Elections and electoral systems have also intensified as a field of academic study, with groundbreaking work over the past decade sharpening our understanding of how electoral systems fundamentally shape the connections among citizens, government, and policy. This volume provides an in-depth exploration of the origins and effects of electoral systems.
6
Julesz, Bela. Dialogues on Perception. The MIT Press, 1994. http://dx.doi.org/10.7551/mitpress/2398.001.0001.
Abstract:
An elucidation of ideas and insights generated by the paradigm of "early vision," presented in the form of dialogues. Renowned for his work in depth perception and pattern recognition, Bela Julesz originated the techniques—involving computer-generated random-dot stereograms, cinematograms, and textures—that resulted in the subfield of human psychology called "early vision." In this book, Julesz elucidates the ideas and insights generated by this exciting paradigm in a series of dialogues between Julesz the naif and Julesz the scientist. These playful, personal, deeply informed dialogues, though challenging, are never beyond the reach of the general scientific reader interested in brain research. Among the topics covered are stereopsis, motion perception, neurophysiology, texture and auditory perception, early vision, visual cognition, and machine vision. Julesz's work on early vision and focal attention is the basis of the discussions, but he is equally at ease recounting his debate with John Searle and describing his interactions with Salvador Dali. He also addresses creativity, mathematics, theories, metascientific questions, maturational windows, and cortical plasticity, relates his current work to past findings and ideas, and considers how some strategic questions can be solved with existing tools.
7
Phillips, Kendall R. Controversial Cinema. Greenwood Publishing Group, Inc., 2008. http://dx.doi.org/10.5040/9798400631719.
Abstract:
At the heart of any history of controversial films is a strange paradox: while films, especially popular and mainstream films, are often portrayed as meaningless products of popular culture, those popular films involved in public controversies become the focal point of enormous cultural energy, political attention, and profoundly conflicting sets of principles. The ongoing culture wars continue to shape the American political landscape, and controversial films continue to be a major point of conflict. Controversial Cinema: The Films that Outraged America traces the history of controversial films and offers insights into why it is that certain films spark controversies, and how Americans typically react to controversial moviemaking. Since the widespread banning of DW Griffith's The Birth of a Nation, the American film industry has found itself embroiled in one political controversy after another. These controversies have centered on everything from the portrayal of the past, as in Griffith's film, to depictions of sex and sexuality, to the use of graphic violence, and issues of race, religion, and politics. In turn, segments of the American public have been driven to boycott, picket, and even censor those films they felt challenged their sense of decency. At the heart of this history of controversial films is a strange paradox: while films, especially popular and mainstream films, are often portrayed as meaningless products of popular culture, popular films involved in public controversies become the focal point of enormous cultural energy and political attention. The ongoing culture wars thus continue to shape the American political landscape, and controversial films continue to be a major point of conflict. In the course of this wide-ranging work, Kendall Phillips offers insights into the kinds of films that spark controversies, and the ways that Americans typically react to them. Organized around broad controversial themes and with particular attention to mainstream films since the dissolution of the Motion Picture Production Code in the mid-1960s, Controversial Cinema explores why films spark broad cultural controversies, how these controversies play out, and the long-term results. The four broad areas of controversy examined in the work are: Sex and Sexuality, Violence, Race, and Religion. Each chapter offers a broad overview of the history of these topics in controversial American films as well as more in-depth examinations of recent examples, including The Silence of the Lambs, Natural Born Killers, Do the Right Thing, and The Passion of the Christ. A final section of the book considers the broader issues of cultural politics in light of the long history of controversial cinema.
8
Wooldredge, John, and Paula Smith, eds. The Oxford Handbook of Prisons and Imprisonment. Oxford University Press, 2016. http://dx.doi.org/10.1093/oxfordhb/9780199948154.001.0001.
Abstract:
The Oxford Handbook on Prisons and Imprisonment provides a rich source of information on institutional corrections around the world, covering the most critical issues facing both inmates and prison staff. The contributors offer theoretically informed and critical discussions of these issues that facilitate more objective and realistic assessments of related problems and their possible solutions. The handbook is the first original volume on prisons and prisoners to cover topics relevant to both the social and behavioral sciences with equal depth paid to each area. Focusing on the impact of these issues on the philosophies of incarceration (retribution, general and specific deterrence, incapacitation, and rehabilitation) is also unique to a single volume, providing a larger picture of their implications. Included are updated discussions of the always popular topics such as conditions of confinement and prisoner subcultures and topics that have taken or are destined to take greater priority in the field such as inmate victimization, special offender populations, prison programs, prisoner re-entry, and privatization. The handbook is divided into six sections corresponding to topic areas identified as major focal points of discussion and research in the field. As such, it provides a single source that bridges social and behavioral science perspectives, providing students with a comprehensive understanding of these topics while providing academics with a knowledge base that will more effectively inform their own research. For practitioners, particularly those in the treatment sector, the book provides an excellent overview of best program practices that are empirically based and research-driven.
9
Marques, Marcia Alessandra Arantes, ed. Perspectivas e reflexões em Sociologia. Bookerfield Editora, 2021. http://dx.doi.org/10.53268/bkf21091600.
Abstract:
A obra em questão, contém nove artigos, voltados para a pesquisa no âmbito das Ciências Sociais. De modo geral, o Estado, sua ausência, ou ainda, questionamentos sobre a atuação do mesmo, está presente em quase todos os capítulos. Entretanto, com um olhar mais apurado, é possível identificar especificidades. Nesse sentido, os artigos selecionados, difundem temas voltados aos mais diversos enfoques, como por exemplo, o Desenvolvimento econômico e desigualdades sociais, Saúde e Estado e a Ação Coletiva. No tema Desenvolvimento econômico, desigualdades sociais e violência, destacam-se três capítulos. O primeiro, “A política econômica do governo Lula: uma análise do I plano de aceleração do crescimento”, de autoria de Nelson Calsavara Garcia Junior, apresenta uma reconstituição da política econômica adotada, como também, tece uma análise do I PAC, colocado em prática no início do segundo mandato desse governo, com vistas à promoção do crescimento e o desenvolvimento econômico. Dividido em quatro partes, o capítulo também contextualiza o cenário político da época. No capítulo seguinte, “Aspectos da prostituição feminina de rua na cidade de Ribeirão Preto/SP: desigualdades, violências e subcidadania”, elaborado por Eulália Fabiano, o foco é revelar, por meio de uma pesquisa empírica, quais são as características do grupo social que essas mulheres pertencem. Contando com três partes, o capítulo ainda traz à tona, as vulnerabilidades econômico-sociais a que o grupo em estudo estava exposto, como a violência e a exploração econômica, mesmo que a localidade escolhida, seja uma referência econômica no país. Para completar esse tema, “Violência doméstica e a busca da ruptura”, da autora Maria Rozilda Barbosa do Nascimento, analisa as percepções de mulheres em situação de violência doméstica egressas na Casa Abrigo Mãe da Mata em Rio Branco, no estado do Acre. Para tanto, o capítulo dispõe de quatro partes e busca compreender, como a intervenção estatal, colaborou para transformar essas vidas. Outra tema em destaque, é a Saúde, onde brilham dois capítulos. O primeiro, “A saúde indígena e as políticas da vida: discussões entre direito e interculturalidade”, de autoria de Fabiana Leticia Sbaraini, expõe o papel exercido pelo Estado e as políticas da vida que modelaram a vida indígena como uma sub-humanidade. Contendo cinco partes, o artigo ainda ressalta a necessidade do estabelecimento de reflexões, para reconhecer diversidades étnicas e culturais que reverberam na saúde indígena. Já no próximo capítulo, “Cirurgia estética e as transformações corporais na contemporaneidade”, elaborado por Áurea Regina Silva Nunes Santos, foca na investigação dos motivos que levam as pessoas a buscarem esses procedimentos, para modificarem seus corpos. O capítulo conta com três partes, para ainda, abordar a percepção das pessoas, antes e depois das cirurgias estéticas. O tema que encerra o livro é Estado e a Ação Coletiva, onde se sobressaem, quatro capítulos. No primeiro, “Segurança pública e pesquisa de vitimização”, o autor Denis Berté Sálvia apresenta um levantamento das pesquisas de vitimização, a nível nacional e internacional, para analisar os arranjos institucionais utilizados. Esse capítulo contém cinco partes, que buscam o entendimento se tais arranjos, agregam valor e contribuem para a produção regular desses tipos de pesquisas. No capítulo seguinte, “Polícia Comunitária em Mato Grosso: tensão entre estado e sociedade”, o autor Sebastião Carlos Rodrigues da Silva, propõe a análise da implantação do projeto de Polícia Comunitária em Cuiabá, com o objetivo de identificar a participação da sociedade, e, se existem as pré-condições para realização do projeto. Esse capítulo possui cinco partes, e ainda, busca revelar o grau de adequação entre os pré-requisitos da Polícia Comunitária e o grau de civismo da sociedade em questão. Já no terceiro capítulo, “Emergencialismo e autoritarismo: um breve ensaio sociológico sobre a investigação criminal”, os autores João Vitor Gomes Pinto e Déborah Dáfne Farias Bigue apresentam uma análise onde o investigado, durante a fase investigativa, é objeto da ação estatal e não sujeito de direitos. O ensaio contém quatro partes, buscando explicar e categorizar o direito penal aplicado, com a utilização das lições de campo bourdieusiano e com a concepção harbermasiana de discurso punitivo. Por fim, o capítulo “Gramsci e Melucci: um diálogo possível para se pensar uma análise da ação coletiva”, da autora Rafaela de Melo Vasconcellos, traz ao debate, uma discussão teórica desses dois pensadores, no que diz respeito, a ação coletiva e aos movimentos sociais. Para tanto, o capítulo conta com três partes e são abordados também, os aspectos de construção hegemônica e à formação da identidade coletiva
Book chapters on the topic "Focal Depths":
1
Guo, Xinqing, Zhang Chen, Siyuan Li, Yang Yang, and Jingyi Yu. "Deep Eyes: Binocular Depth-from-Focus on Focal Stack Pairs." In Pattern Recognition and Computer Vision, 353–65. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-31726-3_30.
2
Koulouri, A., V. Rimpiläinen, M. Brookes, and J. P. Kaipio. "Prior Variances and Depth Un-Biased Estimators in EEG Focal Source Imaging." In EMBEC & NBC 2017, 33–36. Singapore: Springer Singapore, 2017. http://dx.doi.org/10.1007/978-981-10-5122-7_9.
3
Yüksel, F. A., and M. Alpmen. "Time and Space Distributions of Intermediate Focal Depth Earthquakes in the South-West of Turkey." In Comprehensive Approach to Earthquake Disaster Mitigation, 63–81. Wiesbaden: Vieweg+Teubner Verlag, 1993. http://dx.doi.org/10.1007/978-3-322-85461-2_5.
4
Ozbay, Baris N., Gregory L. Futia, Ming Ma, Connor McCullough, Michael D. Young, Diego Restrepo, and Emily A. Gibson. "Miniature Multiphoton Microscopes for Recording Neural Activity in Freely Moving Animals." In Neuromethods, 187–230. New York, NY: Springer US, 2023. http://dx.doi.org/10.1007/978-1-0716-2764-8_7.
Abstract:
AbstractMiniaturized head-mounted microscopes for in vivo recording of neural activity have gained much recognition within the past decade of neuroscience research. In combination with fluorescent reporters, these miniature microscopes allow researchers to record the neural activity that underlies behavior, cognition, and perception in freely moving animals. Single-photon miniature microscopes are convenient for widefield recording but lack the increased penetration depth and optical sectioning capabilities of multiphoton imaging. Here we discuss the current state of head-mounted multiphoton miniature microscopes and introduce a miniature head-mounted two-photon fiber-coupled microscope (2P-FCM) for neuronal imaging with active axial focusing enabled using a miniature electrowetting lens. The 2P-FCM enables three-dimensional two-photon optical recording of structure and activity at multiple focal planes in a freely moving mouse. Detailed methods are provided in this chapter on the 2P-FCM design, operation, and software for data analysis.
5
Michałowski, Andrzej, Milena Teska, Marta Krzyżanowska, Patrycja Kaczmarska, Mateusz Frankiewicz, Marek Żółkiewski, and Przemysław Niedzielski. "About the ‘interim’ or discovering the depths of the pre-Roman Iron Age." In Treasures of Time: Research of the Faculty of Archaeology of Adam Mickiewicz University in Poznań, 312–25. Adam Mickiewicz University Poznan, 2021. http://dx.doi.org/10.14746/wa.2021.18.978-83-946591-9-6.
Abstract:
The pre-Roman Iron Age, i.e. the last five last centuries BC, is one of the most mysterious periods in Polish prehistory and constitutes an extremely interesting research issue, which help concentrate the studies on it, into a compact group of research problems. The studies on the pre-Roman Iron Age carried out by the group of researchers at the Faculty of Archaeology of the Adam Mickiewicz University are based on the research traditions of Poznań archaeology. The focal point of work in recent years has been settlement pottery, which is a mass source acquired during excavations whose potential has not yet been fully exploited. One way to better understand the possibilities that this type of mass material can bring has been exploitation of the potential of archaeometry. The ongoing studies on the problems of the pre-Roman Iron Age strive to detail and explain the processes and changes occurring at the time. They fit into the Poznań tradition of studies on this period, being a continuation of previous work undertaken on its intricate issues – empowering it and leading it out of the titular ‘interim’, placing it in the fully deserved centre of research interests.
6
"focal depth." In Dictionary Geotechnical Engineering/Wörterbuch GeoTechnik, 549. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-642-41714-6_62146.
7
"EFFICIENCY-FOCAL DEPTH AND FIGURE 4.5." In Earthquake Engineering, 92–99. WORLD SCIENTIFIC, 1988. http://dx.doi.org/10.1142/9789814350624_0005.
8
Devaux, Bertrand, Francine Chassoux, Elisabeth Landré, and Baris Turak. "Depth EEG in Sensorimotor Cortex Epilepsy." In Invasive Studies of the Human Epileptic Brain, edited by Samden D. Lhatoo, Philippe Kahane, and Hans O. Lüders, 378–92. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780198714668.003.0028.
Abstract:
Surgery for intractable seizures originating from the sensorimotor cortex is associated with a risk of permanent deficit and a risk of incomplete epileptogenic tissue removal. Depth electrode implantation in the sensorimotor region has been performed over several decades with acceptable morbidity. Motor, sensory, premotor, supplementary motor area, and connected areas (parietal lobe, cingulate gyrus, and insular cortex) are explored with orthogonal and oblique electrodes. Implantation strategy is guided by ictal semiology and by the type of epileptogenic lesion identified on imaging. SEEG may identify (1) an MRI-negative focal cortical dysplasia, frequently localized in the sensorimotor region, (2) the epileptogenic part of a heterotopia or a polymicrogyria, (3) the extent of cortex resection in infantile hemiplegia, as an alternative to hemispherotomy, and may guide stereotactic radiofrequency thermocoagulations of a focal lesion as an alternative to surgical resection.
9
Osmanovic, Smajo. "Imaging." In Glaucoma. Oxford University Press, 2012. http://dx.doi.org/10.1093/oso/9780199757084.003.0010.
Abstract:
•Stereoscopic optic nerve photography has been considered the gold standard for documenting the optic nerve head (ONH)/retinal nerve fiber layer (RNFL) status. •Digital imaging technologies were developed recently to provide reproducible and more objective quantitative assessment of the ONH and RNFL. •Each technology measures different aspects of ONH and RNFL morphology; information obtained from different imaging devices is complementary and can be used to detect different abnormal features in the same patient. •Possible roles of ONH/RNFL imaging in clinical practice: •Documentation of ONH status• Glaucoma diagnosis •Detecting progression •Risk assessment •Screening for glaucoma •CSLO is based on a method of confocal imaging. •A diode laser (670 nm) (Fig 5.1A) scans the surface of posterior pole horizontally and vertically (x- and y-axes) with high speed. Reflected light is detected by a sensor after being filtered by a confocal pinhole which is conjugate to the focal plane of the retina. •By shifting the confocal pinhole, a series of planar scans are acquired at increasing depths and after alignment are combined to create 3-D topographic map of the retina and ONH surface. •Commercially available CSLO devices with major features are listed in Table 5.1. •Image acquisition with Heidelberg Retinal Tomography (HRT) is fast; single tomographic slices are captured in only 24 ms (faster than involuntary saccades or fixation movements). •Pupillary dilation is not needed. •Good images require adequate patient positioning, good fixation, clear media, appropriate focus, and centering the optic nerve in the image. •16 to 64 planar scans are acquired per set. Unusable scans are replaced by software until three useful sets are obtained. •The operator defines the optic disc margin by drawing a contour line along scleral ring. • A reference plane is determined by the HRT software 50 μm below the average height of the contour line in the inferior temporal quadrant. All structures above the reference plane and within the contour line are defined as a neuroretinal rim and are shown as blue (sloped) and green (flat) areas on the topography image (Fig 5.2c).
10
Selden, Nathan R. "Cortical Dysplasia With Extratemporal Epilepsy." In Functional Neurosurgery, C10—C10.P61. Oxford University PressNew York, 2019. http://dx.doi.org/10.1093/med/9780190887629.003.0010.
Abstract:
Abstract Medically refractory focal epilepsy in childhood is often related to the presence of focal cortical dysplasia, which may occur in temporal or extra-temporal locations. Normal findings with standard MR imaging is not unusual in such cases, related to immature myelination or insensitive imaging protocols, or both. High Tesla MR imaging and re-imaging at an older age may provide evidence of focal dyplasia as a possible cause for seizure onset. Invasive epilepsy and functional mapping in children and adolescents may require the placement of subdural grid and/or intraparenchymal depth electrodes, with extra-operative mapping of seizure foci and functional brain tissue. Second stage surgery is then utilized for hardware removal and simultaneous cortical resection to treat the epileptic focus. Although the prognosis for Engel Class I result is lower with extra-temporal foci, it is higher with Type II focal cortical dyplasia, particularly balloon cell dysplasia (Type IIb).
Conference papers on the topic "Focal Depths":
1
Mariné, Maximiliano, Maximiliano V. Valdés, and Vicente J. Parot. "Single-shot Multifocal Microscopy by Virtual Array Imaging." In Novel Techniques in Microscopy. Washington, D.C.: Optica Publishing Group, 2023. http://dx.doi.org/10.1364/ntm.2023.nm2c.3.
Abstract:
Current single-shot multifocal imaging requires beam splitters or diffractive elements. We used a mirror cavity to capture an array of virtual images with offset focal depth on a camera. Focusing at multiple depths is demonstrated.
2
Ormeni, Rrapo, Ethem Bejko, Albana Hasimi, Klodjan Skrame, and Dionald Mucaj. "ASSESSMENT OF SEISMOACTIVE LAYERS IN ELBASANI GEOTERMAL ZONE, ALBANIA." In 23rd SGEM International Multidisciplinary Scientific GeoConference 2023. STEF92 Technology, 2023. http://dx.doi.org/10.5593/sgem2023/1.1/s05.63.
Abstract:
Albania is part of one of the most active seismic regions in Europe with dozens of devastating earthquakes throughout history. In this study, we will present an investigation of the earthquakes of the Elbasani region, in terms of the location accuracy and analysis of the features of the seismoactive layers. The distribution of focal depth shows the activation of a lithospheric zone, which extends in depth between 0 and 40 km. Accurate assessment of seismoactive layers of the Elbasani zone is of great interest in the recognition of the real depth of seismic energy generation and relations with low velocity layers. The depth of earthquakes has particular interest in the case of moderate and strong earthquakes because it is related to their effect on the surface. Strong earthquakes with shallow focal depth cause greater damage than earthquakes of the same magnitude but with a deeper focal depth. The b-value depth analysis is related to the stresses for the seismoactive layers. The crustal structure of the Elbasani zone with high b-values is likely to be associated with crustal low-velocity zones. The earthquakes are relatively smaller beneath the low-velocity zones where the high heat flow values are observed. The location of moderate earthquakes with depths from 20 to 35 km, which means less surface effect than the same earthquake with a depth smaller than 10km. The intensity in the epicenter is dependent by the magnitude and by the focal depth. Analysis of these earthquakes show that shocks with Ml > 4.5 have greater depths than earthquakes with smaller magnitudes. This analysis shows that the seismoactive layer in Elbasani zone lies at a depth of about 30 km. These results are a step towards more detailed geodynamic and seismotectonic analysis.
3
Komatsu, Makoto, Tsutomu Saito, Eiichi Sato, Kazuyoshi Takayama, Toshio Hukui, Teiichi Ohkouchi, Eiji Ishikawa, et al. "Development of a high-speed CMOS drum camera with multiple focal depths." In 26th International Congress on High-Speed Photography and Photonics, edited by Dennis L. Paisley, Stuart Kleinfelder, Donald R. Snyder, and Brian J. Thompson. SPIE, 2005. http://dx.doi.org/10.1117/12.578649.
4
Bloxom, Andrew L., Karl D. von Ellenrieder, Matthew R. Anderson, Ryan S. Mieras, and William S. Weidle. "Wave Height Measurements Behind Submerged Lens-Shaped Structures." In ASME 2011 30th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2011. http://dx.doi.org/10.1115/omae2011-49102.
Abstract:
The ability of submerged lens-shaped structures to focus linear surface waves in deep water is explored through a series of experimental tests in a wave making basin. Three lenses were designed using a combination of linear strip theory and a surface wave analogy to geometrical optics. Two of these lenses were designed to focus waves of a single wavelength of 0.482 m (18.97 in.), one with a focal length to lens width ratio (f-number) of 2.0 and the other with an f-number of 0.5. The third lens was designed to function as a compound lens that could focus a range of wavelengths of between 0.39 m (15.37 in.) and 0.694 m (27.32 in.) at an f-number of 2.0. Using resistance wave height gauges, the sensitivity of wave height at the focus to variations in wavelength from between 0.39 m (15.37 in.) to 0.61 m (24.01 in.) was experimentally measured for all three lenses; the sensitivity of wave height at the focus to variations of lens depths of submergence spanning the range of between 0.75 to 1.25 times the design submergence depth was also explored for the two simple lenses. It was found that the linear strip theory and geometrical optics approach predicted the wave amplification to within ten percent at the design wavelengths and depths, but that the longitudinal position of the experimentally observed focal lengths differed substantially from that expected, by as much as a factor of 2.2 for an f-number of 0.5. Additionally, while the theory predicted a single focal point for each lens, multiple focal points were found to exist behind the compound lens.
5
Guerra, Reynaldo G., Van Carey, Boris Rubinsky, and Mitchel Berger. "Characterization of the Focal Cooling Necessary to Suppress Spontaneous Epileptiform Activity." In ASME/JSME 2007 Thermal Engineering Heat Transfer Summer Conference collocated with the ASME 2007 InterPACK Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/ht2007-32034.
Abstract:
It has been established that focal cooling to suppress epileptiform activity has become a real and viable option. However, the specific thermal parameters necessary to suppress epileptiform activity have only begun to be quantitatively defined. In 2002 it was reported that a 41 year-old man with medically intractable epilepsy undertook surgery to remove his tumor and resect adjacent epileptogenic tissue. Electrocorticography was performed before resection. Cold saline was impinged on the resulting interictal spike foci resulting in transient, complete cessation of spiking. We present a transient post-operative heat transfer analysis of the cold saline impingement on the surface of brain. An approximate temporal and spatial temperature distribution of the perfused human brain response to surface cooling was developed. The realistic extent of cooling below the brain surface due to impinging saline was quantified. The sensitivity of cooling penetration depth to (a) saline exit velocity from the syringe, and (b) syringe inside diameter, was evaluated. A parametric study was performed to characterize the effects of brain metabolism and blood perfusion on surface cooling. The required thermal parameters necessary to suppress epileptiform activity through focal cooling are here quantitatively approximated, i.e. heat flux removal and maximum and realistic cooling penetration depths. The relatively shallow penetration depth suggests that the spreading depolarization associated with epileptiform activity may be abolished through focal cooling without affecting the deeper neurons responsible for motor activity.
6
Herak, Marijan, and Davorka Herak. "PETRINJA EARTHQUAKE AFTERSHOCKS – LOCATIONS, FOCAL MECHANISMS AND RELATED COULOMB STRESS CHANGE." In 2nd Croatian Conference on Earthquake Engineering. University of Zagreb Faculty of Civil Engineering, 2023. http://dx.doi.org/10.5592/co/2crocee.2023.98.
Abstract:
Almost 14000 aftershocks have been located in the first six month after the Mw 6.4 Petrinja earthquake of 29 December 2020. Most epicentres lie close to the NW–SE striking right-lateral causative fault, but considerable activity has been recorded in the surrounding area up to about 50 km away. The hypocentres reach depths of over 20 km, with most of activity recorded between the depths of 5 and 16 km. Their spatial pattern reveals activation of a number of smaller faults. The 75 focal mechanism solutions computed using the first motion polarities read from the seismograms of the local and regional seismic networks, indicate that about half of the aftershocks exceeding magnitude M = 3.0 occurred on strike-slip faults, while the large majority of the remaining ones were due to almost pure reverse dip-slip faulting. Analyses of the Coulomb stress change on optimally oriented strike-slip and dip-slip faults following the mainshock rupture, reveals that a large majority of aftershocks occurred in the volumes characterised by the Coulomb static stress increase, whereas the areas where the effective stress decreased remained mostly quiet. The distribution and preferred strike directions of strike-slip and reverse faulting inferred by the Coulomb stress transfer analyses are also in good agreement with individual focal mechanisms.
7
Du, Xiaohan, Camilo Florian, and Craig B. Arnold. "High depth of field and high speed variable focus for advanced laser processing applications." In Conference on Lasers and Electro-Optics/Pacific Rim. Washington, D.C.: Optica Publishing Group, 2022. http://dx.doi.org/10.1364/cleopr.2022.ctup5a_01.
Abstract:
We use an ultrafast varifocal lens to achieve quasi-simultaneous multi-focal laser marking and scribing of transparent materials. Multiple lines located at different depths in the substrate are produced with a single laser pass.
8
Bagramyan, Arutyun, Tigran Galstian, and Armen Saghatelyan. "Motion free micro-endoscopic system for imaging in freely behaving animals at variable focal depths using liquid crystal lenses (Conference Presentation)." In Three-Dimensional and Multidimensional Microscopy: Image Acquisition and Processing XXVI, edited by Thomas G. Brown and Tony Wilson. SPIE, 2019. http://dx.doi.org/10.1117/12.2508929.
9
Wolken, Jerome J. "The design of an optical scope for the visually impaired." In OSA Annual Meeting. Washington, D.C.: Optica Publishing Group, 1990. http://dx.doi.org/10.1364/oam.1990.tus6.
Abstract:
In search of innovative optical systems, I have turned to the eye structure of rare, deep sea animals that live at depths of 200500 m, where the light is limited and comes primarily from bioluminescence. Eyes have considerable inventiveness in their optical design among these marine animals. In the crustacean copepod copilia the eye has a biconvex lens (L1) and, at some distance away, an aspherical lens (L2), a telescopic eye. The shape of the L2 lens is optimized for light collection and acts like a fiber-optic bundle. The focal point of the optics is a small area of the retina. The retina rapidly moves back and forth, and the organism's eye scans much like the electron beam scans a television screen. The animal's eye structure was modeled, and lenses L1 and L2 (glass and polymers) were shaped into the calculated curvatures and geometry. The focal lengths of the lenses were determined and fitted into an optical scope. The scope was tested for imaging of near, far, and moving objects. Sharp images were obtained from 25 cm to infinity at relatively low light levels. Tests of prototype scopes indicate that they have application for the visually impaired, and the lens L2 can be adapted for optical scanning, photography, and solar energy collection.
10
Piliavin, Michael A., B. J. Herman, and G. Gal. "Near-field diffraction analysis for binary optical elements." In OSA Annual Meeting. Washington, D.C.: Optica Publishing Group, 1990. http://dx.doi.org/10.1364/oam.1990.tuj5.
Abstract:
The analysis of the performance of a binary optical element requires a physical optics calculation because of the diffractive nature of such elements. We have developed a number of software tools for this analysis, which are based on the Kirchhoff-Fresnel diffraction integral. These tools allow investigation of results of diffraction both in and out of the focal plane. The programs take a given (nonbinary) element, convert it to a binary element with prescribed etching resolutions and etching depths, and perform the diffractive calculation. The diffraction is calculated by a number of means (direct numerical integration, Fresnel approximation, evaluation of analytic formulas). The software also computes quantitative measures of performance, such as blur spot sizes, diffraction efficiencies, and wavelength separation (for dispersive elements). We discuss the abilities and limitations of the codes and present sample calculations.
Reports on the topic "Focal Depths":
1
Bent, A. L. Focal mechanisms and depths of aftershocks of the 2010 Haiti earthquake. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2011. http://dx.doi.org/10.4095/288018.
2
Plourde, A. P., and J. F. Cassidy. Mapping tectonic stress at subduction zones with earthquake focal mechanisms: application to Cascadia, Japan, Nankai, Mexico, and northern Chile. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/330943.
Abstract:
Earthquake focal mechanisms have contributed substantially to our understanding of modern tectonic stress regimes, perhaps more than any other data source. Studies generally group focal mechanisms by epicentral location to examine variations in stress across a region. However, stress variations with depth have rarely been considered, either due to data limitations or because they were believed to be negligible. This study presents 3D grids of tectonic stress tensors using existing focal mechanism catalogs from several subduction zones, including Cascadia, Japan, Nankai, Mexico, and northern Chile. We bin data into 50 x 50 x 10 km cells (north, east, vertical), with 50% overlap in all three directions. This resulted in 181380 stress inversions, with 90% of these in Japan (including Nankai). To the best of our knowledge, this is the first examination of stress changes with depth in several of these regions. The resulting maps and cross-sections of stress can help distinguish locked and creeping segments of the plate interface. Similarly, by dividing the focal mechanism catalog in northern Japan into those before and those &gt;6 months after the 2011 Mw 9.1 Tohoku-Oki earthquake, we are able to produce detailed 3D maps of stress rotation, which is close to 90° near the areas of highest slip. These results could inform geodynamic rupture models of future megathrust earthquakes in order to more accurately estimate slip, shaking, and seismic hazard. Southern Cascadia and Nankai appear to have sharp stress discontinuities at ~20 km depth, and northern Cascadia may have a similar discontinuity at ~30 km depth. These stress boundaries may relate to rheological discontinuities in the forearc, and may help us unravel how forearc composition influences subduction zone behaviour and seismic hazard.
3
Murphy, J. R., B. W. Barker, M. E. Marshall, and W. L. Rodi. Improved Focal Depth Determination for Use in Seismic Monitoring of the Underground Nuclear Explosions. Fort Belvoir, VA: Defense Technical Information Center, November 2003. http://dx.doi.org/10.21236/ada422863.
4
Lamontagne, M. Focal depth of earthquakes of the St. Lawrence Valley based on crustal phases recorded within 100 km epicentral distance. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2016. http://dx.doi.org/10.4095/299138.
5
Ma, S., and M. Lamontagne. Earthquakes of the St. Lawrence Valley between Montreal and Québec: focal depth determination from Regional Depth Phases for the magnitude 2.8 and larger earthquakes for the time period 1980-2014. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2017. http://dx.doi.org/10.4095/304228.
6
Hallett, J. B. L51525 Sizing of Girth Weld Defects Using Focused Ultrasonic Beams. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), January 1987. http://dx.doi.org/10.55274/r0010202.
Abstract:
This project was produced to evaluate the performance of focused beams in sizing and positioning defects in pipeline girth welds. The sound beams from standard flat transducers were focused using acoustic lenses. Two types of plastics, having different sound velocities are used in the design of these lenses. One is used for the lens and the other for the wedge. The profile of the lens/wedge boundary was designed to focus the sound at a selected depth. The design takes into account the beam angle, beam diameter, focal point and working range required. The effects of test surface curvature were also incorporated into the design. This project was conducted in three phases using sample welds containing real defects, such as root cracks, slag and lack of sidewall fusion. In Phase III the individual defect size predictions were compared to the actual defects found during destructive examination. Only the readings where the signal sources could be positively identified as defects by breaking open or sectioning were included. All measurements were made to the nearest 0.5 mm (0.02 inches).
7
West, Chris, Rhian Ebrey, Joe Simpson, Emilie Stokeld, Frida Lager, Simon Croft, Francesco Bosello, et al. Report on preliminary impact and policy insights from model and sectoral case study analysis: trade-linked cross-border impacts. Stockholm Environment Institute, January 2023. http://dx.doi.org/10.55317/casc025.
Abstract:
Trade-linked cross-border climate impacts have the potential to severely disrupt the European economy. Yet, the research landscape that surrounds these potential impacts remains in a relatively nascent stage. Importantly, whilst quantitative approaches can be applied in isolation to develop our understanding of cascading cross-border impacts, these should ideally be supplemented by the broader development of knowledge as to how initial climate triggers might evolve via trade systems, might interact with the actions and activities of supply chain actors, and how the wider policy landscape might act as an enabler or barrier to EU climate resilience. The objective of this deliverable is to provide a set of preliminary policy insights resulting from a summary and synthesis of outputs from WP3 of the CASCADES project. Outputs of WP3 encompass the quantitative results of models applied to the exploration of the impacts of climate change on EU trade-linked systems, and qualitative analysis of stakeholder viewpoints – supplemented by information from the wider literature – which highlights key climate-linked concerns, potential responses, and interactions with policy. The deliverable is divided below into three main sections. The first provides a synthesis and related policy implications based on a summary of the outcomes of research activities conducted in CASCADES WP3. Then, the remainder of the report is divided into discrete summaries of the analysis conducted. Analysis Section 1 summarises the quantitative outcomes of WP3 models. Analysis Section 2 summarises the qualitative components of WP3 within the form of three focal trade-linked case studies: a) food systems, b) the soy supply chain, c) energy transition minerals. The depth and breadth of these three case studies differs (more explanation on scope of coverage and methods applied can be found in Analysis Section 2). The Deliverable overall is intended to act as a starting point for (for food systems and soy supply chains) a more in-depth exploration of the policy environment that surrounds trade-linked cross-border impacts that will link to WP6 of the CASCADES project.
8
Specification of source zones, recurrence rates, focal depths, and maximum magnitudes for earthquakes affecting the Savannah River site in South Carolina. US Geological Survey, 1992. http://dx.doi.org/10.3133/b2017.