Large-scale computer-generated absorption holograms of 3D objects: I. Theoretical background and visual concepts

1999 ◽  
Author(s):  
Colin D. Cameron ◽  
Douglas A. Payne ◽  
David T. Sheerin ◽  
Christopher W. Slinger ◽  
Nicholas J. Phillips ◽  
...  
Keyword(s):  
Large Scale ◽  
Theoretical Background ◽  
3D Objects ◽  
Visual Concepts

Application of Wide-Band Ultrasound for the Detection of Angled Crack Features in Oil and Gas Pipelines

2018 ◽  
Author(s):  
Willem Vos ◽  
Petter Norli ◽  
Emilie Vallee
Keyword(s):  
Large Scale ◽  
Crack Detection ◽  
Oil And Gas ◽  
Wide Band ◽  
Theoretical Background ◽  
Proof Of Concept ◽  
Offshore Pipelines ◽  
Large Scale Testing ◽  
Theoretical Predictions ◽  
Set Up

This paper describes a novel technique for the detection of cracks in pipelines. The proposed in-line inspection technique has the ability to detect crack features at random angles in the pipeline, such as axial, circumferential, and any angle in between. This ability is novel to the current ILI technology offering and will also add value by detecting cracks in deformed pipes (i.e. in dents), and cracks associated with the girth weld (mid weld cracks, rapid cooling cracks and cracks parallel to the weld). Furthermore, the technology is suitable for detection of cracks in spiral welded pipes, both parallel to the spiral weld as well as perpendicular to the weld. Integrity issues around most features described above are not addressed with ILI tools, often forcing operators to perform hydrostatic tests to ensure pipeline safety. The technology described here is based on the use of wideband ultrasound inline inspection tools that are already in operation. They are designed for the inspection of structures operating in challenging environments such as offshore pipelines. Adjustments to the front-end analog system and data collection from a grid of transducers allow the tools to detect cracks in any orientation in the line. Description of changes to the test set-up are presented as well as the theoretical background behind crack detection. Historical development of the technology will be presented, such as early laboratory testing and proof of concept. The proof of concept data will be compared to the theoretical predictions. A detailed set of results are presented. These are from tests that were performed on samples sourced from North America and Europe which contain SCC features. Results from ongoing testing will be presented, which involved large-scale testing on SCC features in gas-filled pipe spools.

scholarly journals A Spatial Analysis Approach to Understanding Caddoan Mounds in the Arkansas River Drainage

2004 ◽  
Author(s):  
Gregory Vogel
Keyword(s):  
Spatial Analysis ◽  
Spatial Data ◽  
Large Scale ◽  
Theoretical Background ◽  
Gis Analysis ◽  
Arkansas River ◽  
Gis Modeling ◽  
River Drainage ◽  
The People ◽  
Computationally Intensive

In this article I present a theoretical framework for understanding Caddoan mounds in the central Arkansas River drainage and the implications they may hold for the social structure and environmental adaptations of the people who made them. The power and efficiency of Geographic Information Systems (GIS) modeling now allows for large-scale, computationally intensive spatial analysis simply not possible before. Questions of landscape organization or spatial relationships that previously would have taken months or even years to answer can now be solved in a matter of minutes with GIS and related technologies, given the appropriate datasets. Quite importantly, though, such analyses must first be placed in context and theory if they are to be meaningful additions to our understanding of the past. While it is conventional to refer to “GIS analysis” (and I use the term in this article), it is important to keep in mind that data manipulations alone are not analysis. GIS, along with statistical software and related computer technologies, are tools of spatial analysis just as shovels and trowels are tools of excavation. Such tools can organize and reveal information if they are employed carefully, but the tools themselves have no agency and cannot interpret anything on their own. The terms “GIS analysis” or “GIS interpretation” are therefore somewhat misnomers, just as “trowel analysis” or “trowel interpretation” would be. It is not the GIS, or any component of it, that does the analysis or interpretation; it simply manipulates spatial data. We interpret these manipulations based upon theoretical background, previous research, and the questions we wish to answer.

History of Additive Manufacturing

2017 ◽  
pp. 1-24 ◽  
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Large Scale ◽  
Selective Laser Sintering ◽  
3D Printer ◽  
3D Objects ◽  
History Of ◽  
Pros And Cons ◽  
3D Printed ◽  
The Common

History of additive manufacturing started in the 1980s in Japan. Stereolithography was invented first in 1983. After that tens of other techniques were invented under the common name 3D printing. When stereolithography was invented rapid prototyping did not exists. Tree years later new technique was invented: selective laser sintering (SLS). First commercial SLS was in 1990. At the end of 20t century, first bio-printer was developed. Using bio materials, first kidney was 3D printed. Ten years later, first 3D Printer in the kit was launched to the market. Today we have large scale printers that printed large 3D objects such are cars. 3D printing will be used for printing everything everywhere. List of pros and cons questions rising every day.

Mechatronic System Integration for Senior Students

2006 ◽  
Author(s):  
Dana Kulic ◽  
Elizabeth Croft
Keyword(s):  
System Integration ◽  
Interface Design ◽  
Large Scale ◽  
Discrete Event ◽  
Practical Experience ◽  
Theoretical Background ◽  
Mechatronic System ◽  
Autonomous Sensor ◽  
Field Programmable ◽  
Laboratory Component

This paper describes the design and implementation of a senior level course in mechatronic system integration for students completing a mechatronics engineering option in mechanical engineering. The course is designed to give students theoretical and practical experience with a large-scale mechatronic system, and a variety of control, sensing and actuating architectures. The lecture component of the course introduces students to large-scale project integration and interface design, as well as system architecture design. Students learn about alternative control hardware platforms commonly used in industry, such as motion control hardware, field programmable gate arrays and programmable logic controllers. The selection and system integration of various industrial sensors, including vision, are presented. Students also learn about networked control and discrete event control approaches for large-scale industrial systems. The course contains a significant practical laboratory component. In a series of laboratory sessions, students develop and implement subsystems of a part sorting machine, culminating in the integration and demonstration of an automated, autonomous, sensor driven electro-mechanical system for sorting randomly delivered parts. The course offers students a theoretical background as well as significant practical experience with large scale mechatronics systems, as would be encountered in industry. This paper describes the lecture and laboratory content, and the experiences from the first offering of the course.

scholarly journals BRLO-Tree: A Data Structure Used for 3D GIS Dynamic Scene Rendering

2015 ◽  
Vol 15 (4) ◽  
pp. 124-137 ◽  
Author(s):  
Wenju Wang ◽  
Zhang Xuan ◽  
Liujie Sun ◽  
Zhongmin Jiang ◽  
Jingjing Shang
Keyword(s):  
Data Structure ◽  
Large Scale ◽  
Three Dimensional ◽  
Level Of Detail ◽  
Dynamic Scene ◽  
3D Gis ◽  
Dynamic Scenes ◽  
Complex Dynamic ◽  
3D Objects ◽  
System A

Abstract BRLO-Tree (Block-R-Tree-Loose-Octree) is presented in this paper based on the R-Tree and Loose-Octree. The aim of the structure is to visualize the large scale and complex dynamic scenes in a 3D (three-dimensional) GIS (Geographic Information System). A new method of clustering rectangles to construct R-tree based on an improved K-means algorithm is put forward. Landform in 3D GIS is organized by R-Tree. The block is used as the basic rendering unit. The 3D objects of each block are respectively organized by a Loose-Octree. A series of techniques, based on this data structure, such as LOD (Level of Detail), relief impostors are integrated. The results of the tests show that BRLO-Tree cannot only support the large scale 3D GIS scene exhibition with wandering and fighting, but it can also efficiently manage the models in a dynamic scene. At the same time, a set of integrated techniques based on BRLO-Tree can make the rendering pictures more fluence and the rendering time vastly improved.

scholarly journals Dynamic control of hippocampal spatial coding resolution by local visual cues

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Romain Bourboulou ◽  
Geoffrey Marti ◽  
François-Xavier Michon ◽  
Elissa El Feghaly ◽  
Morgane Nouguier ◽  
...  
Keyword(s):  
Hippocampal Neurons ◽  
Visual Cues ◽  
Large Scale ◽  
Dynamic Control ◽  
Local Features ◽  
Temporal Coding ◽  
Spatial Coding ◽  
3D Objects ◽  
Phase Precession ◽  
Fast Adaptation

The ability to flexibly navigate an environment relies on a hippocampal-dependent cognitive map. External space can be internally mapped at different spatial resolutions. However, whether hippocampal spatial coding resolution can rapidly adapt to local features of an environment remains unclear. To explore this possibility, we recorded the firing of hippocampal neurons in mice navigating virtual reality environments, embedding or not local visual cues (virtual 3D objects) in specific locations. Virtual objects enhanced spatial coding resolution in their vicinity with a higher proportion of place cells, smaller place fields, increased spatial selectivity and stability. This effect was highly dynamic upon objects manipulations. Objects also improved temporal coding resolution through improved theta phase precession and theta timescale spike coordination. We propose that the fast adaptation of hippocampal spatial coding resolution to local features of an environment could be relevant for large-scale navigation.

scholarly journals Linking Instruction and Student Achievement. A research design for a new generation of classroom studies

2017 ◽  
Vol 11 (3) ◽  
pp. 10 ◽  
Author(s):  
Kirsti Klette ◽  
Marte Blikstad-Balas ◽  
Astrid Roe
Keyword(s):  
Student Achievement ◽  
Large Scale ◽  
Classroom Practices ◽  
Instructional Quality ◽  
Theoretical Background ◽  
Video Data ◽  
Data Sources ◽  
Future Research ◽  
Ongoing Research ◽  
Achievement Data

AbstractEducational research into instructional quality would benefit from macro- and meso-level instructional data – such as achievement data or large-scale student surveys – in relation to data from the micro level – such as detailed analyses of classroom practices. Several scholars have specifically asked for studies that correlate achievement data with records of learning processes and teaching strategies, and ongoing projects attempting to do so have shown promising results. Linking different data sources on instructional quality is quite demanding because it requires a concerted effort by researchers from different fields of expertise and different traditions. A main ambition of our ongoing research project is precisely to advance such integration. As the title of the project reveals, we are dedicated to Linking Instruction and Student Achievement (LISA). In this article, we start by providing a theoretical background and status of knowledge related to instructional quality. We go on to argue that video data has shown particular promise in studies aiming to obtain systematic data from a range of classrooms in order to compare classroom practices. We then present the three components of the LISA project’s design – student perception surveys, systematic classroom observation, and achievement gains in national tests – and the value of combining these three data sources. Finally, we will outline some of our findings thus far and point to future research possibilities.Key words: instructional quality; classroom practices; video studies; mathematics; language arts Å koble undervisning med elevprestasjoner - Forskningsdesign for en ny generasjon klasseromsstudierSammendragFor å studere undervisningskvalitet vil det være en fordel å kombinere data fra et makro og meso- nivå  med detaljerte studier av hva som skjer i klasserommet. Flere har etterlyst studier som ser på sammenhenger mellom målbar faglig fremgang og lærerens undervisning. Å få til slike studier er krevende, da det forutsetter et tett samarbeid mellom forskere fra ulike felt med ulik ekspertise innenfor nokså ulike forskningstradisjoner. En hovedambisjon i vårt pågående forskningsprosjekt er nettopp å få til en slik integrasjon. Som tittelen avslører, er vi dedikert til «Linking Instruction and Student Achievement (LISA)». I denne artikkelen presenterer vi det teoretiske og empiriske grunnlaget knyttet til undervisningskvalitet. Videre argumenterer vi for verdien av videodata i studier som sammenligner undervisningspraksiser fra ulike klasserom på en systematisk måte. Deretter presenterer vi de tre datakildene i LISA-prosjektets forskningsdesign – spørreskjemaer til elever om deres oppfatninger om lærerens undervisning, systematiske klasseromsobservasjoner, og målt fremgang på nasjonale prøver i lesing og regning. Verdien av å kombinere nettopp disse tre datakildene vil også bli diskutert. Avslutningsvis deler vi noen av våre tidlige forskningsfunn.Nøkkelord: undervisningskvalitet; klasseromspraksis; video studier; matematikk; norskfaget

Content-Based Video Indexing and Retrieval

2011 ◽  
pp. 110-144
Author(s):  
Jianping Fan ◽  
Xingquan Zhu ◽  
Jing Xiao
Keyword(s):  
Video Compression ◽  
Large Scale ◽  
Video Retrieval ◽  
Retrieval Systems ◽  
Database Indexing ◽  
Visual Concepts ◽  
Representation Scheme ◽  
High Level ◽  
Video Retrieval Systems ◽  
Content Based Video Retrieval

Recent advances in digital video compression and networks have made videos more accessible than ever. Several content-based video retrieval systems have been proposed in the past.  In this chapter, we first review these existing content-based video retrieval systems and then propose a new framework, called ClassView, to make some advances towards more efficient content-based video retrieval. This framework includes: (a) an efficient video content analysis and representation scheme to support high-level visual concept characterization; (b) a hierarchical video classification technique to bridge the semantic gap between low-level visual features and high-level semantic visual concepts; and (c) a hierarchical video database indexing structure to enable video access over large-scale database. Integrating video access with efficient database indexing tree structures has provided a great opportunity for supporting more powerful video search engines.

Modeling Neuronal Assemblies: Theory and Implementation

2001 ◽  
Vol 13 (9) ◽  
pp. 1923-1974 ◽  
Author(s):  
J. Eggert ◽  
J. L. van Hemmen
Keyword(s):  
Large Scale ◽  
Theoretical Background ◽  
Spiking Neurons ◽  
Spike Response ◽  
Macroscopic Models ◽  
Neuronal Assemblies ◽  
Large Scale Network ◽  
Graded Response ◽  
Scale Network ◽  
Network Simulations

Models that describe qualitatively and quantitatively the activity of entire groups of spiking neurons are becoming increasingly important for biologically realistic large-scale network simulations. At the systems and areas modeling level, it is necessary to switch the basic descriptional level from single spiking neurons to neuronal assemblies. In this article, we present and review work that allows a macroscopic description of the assembly activity. We show that such macroscopic models can be used to reproduce in a quantitatively exact manner the joint activity of groups of spike-response or integrate-and-fire neurons. We also show that integral as well as differential equation models of neuronal assemblies can be understood within a single framework, which allows a comparison with the commonly used assembly-averaged graded-response type of models. The presented framework thus enables the large-scale neural network modeler to implement networks using computational units beyond the single spiking neuron without losing much biological accuracy. This article explains the theoretical background as well as the capabilities and the implementation details of the assembly approach.

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