scholarly journals PPAP: Perspective Projection Augment Platform with Pan–Tilt Actuation for Improved Spatial Perception

Sensors ◽  
2019 ◽  
Vol 19 (12) ◽  
pp. 2652
Author(s):  
JungHyun Byun ◽  
Tack-Don Han
Keyword(s):  
Augmented Reality ◽  
Depth Perception ◽  
Spatial Perception ◽  
Spatial Relationship ◽  
User Studies ◽  
Servo Control ◽  
Virtual Object ◽  
Perspective Projection ◽  
User Perspective ◽  
Relationship Of

In this paper, we propose PPAP, an augmented reality platform with an actuated projector for dynamic user-perspective projection. In PPAP, a stationary camera is used jointly with a pan–tilt motorized projector-camera unit. With the servo control of the steerable pan–tilt system, the system is able to continuously orient itself to match the user’s view center of the projection-mapped surface. This provides users with greatly widened viewing angles in the augmented scene, when compared to the stationary projection. Through user studies, in which users judged the size and distance of a projected virtual object, we verified that the perspective projection with the actuated projector helps users better understand the spatial relationship of the virtual object in the augmented scene in terms of depth perception.

scholarly journals Medical Augmented-Reality Visualizer for Surgical Training and Education in Medicine

2019 ◽  
Vol 9 (13) ◽  
pp. 2732 ◽  
Author(s):  
Radosław Gierwiało ◽  
Marcin Witkowski ◽  
Maciej Kosieradzki ◽  
Wojciech Lisik ◽  
Łukasz Groszkowski ◽  
...  
Keyword(s):  
Augmented Reality ◽  
Spatial Perception ◽  
Spatial Relationship ◽  
Guidance System ◽  
Training And Education ◽  
3D Perception ◽  
Augmented Reality System ◽  
Internal Structures ◽  
Medical Augmented Reality ◽  
Liver Phantom

This paper presents a projection-based augmented-reality system (MARVIS) that supports the visualization of internal structures on the surface of a liver phantom. MARVIS is endowed with three key features: tracking of spatial relationship between the phantom and the operator’s head in real time, monoscopic projection of internal liver structures onto the phantom surface for 3D perception without additional head-mounted devices, and phantom internal electronic circuit to assess the accuracy of a syringe guidance system. An initial validation was carried out by 25 medical students (12 males and 13 females; mean age, 23.12 years; SD, 1.27 years) and 3 male surgeons (mean age, 43.66 years; SD, 7.57 years). The validation results show that the ratio of failed syringe insertions was reduced from 50% to 30% by adopting the MARVIS projection. The proposed system suitably enhances a surgeon’s spatial perception of a phantom internal structure.

Ultrastructural evidence for mast cell-macrophage interrelationships in the dura mater of the rat: Infrequent mast cell-nerve associations

1990 ◽  
Vol 48 (3) ◽  
pp. 352-353
Author(s):  
Ruth V.W. Dimlich
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Dura Mater ◽  
Spatial Relationship ◽  
Potassium Phosphate ◽  
Plasma Extravasation ◽  
Close Spatial Relationship ◽  
Male Wistar Rats ◽  
Headache Pain ◽  
Relationship Of

Mast cells in the dura mater of the rat may play a role in cerebral pathologies including neurogenic inflammation (vasodilation; plasma extravasation) and headache pain . As has been suggested for other tissues, dural mast cells may exhibit a close spatial relationship to nerves. There has been no detailed ultrastructural description of mast cells in this tissue; therefore, the goals of this study were to provide this analysis and to determine the spatial relationship of mast cells to nerves and other components of the dura mater in the rat.Four adult anesthetized male Wistar rats (290-400 g) were fixed by perfusion through the heart with 2% glutaraldehyde and 2.8% paraformaldehyde in a potassium phosphate buffer (pH 7.4) for 30 min. The head of each rat was removed and stored in fixative for a minimum of 24 h at which time the dural coverings were removed and dissected into samples that included the middle meningeal vasculature. Samples were routinely processed and flat embedded in LX 112. Thick (1 um) sections from a minimum of 3 blocks per rat were stained with toluidine blue (0.5% aqueous).

scholarly journals Geo-Spatial Analysis of Population Density and Annual Income to Identify Large-Scale Socio-Demographic Disparities

2021 ◽  
Vol 10 (7) ◽  
pp. 432
Author(s):  
Nicolai Moos ◽  
Carsten Juergens ◽  
Andreas P. Redecker
Keyword(s):  
Population Density ◽  
Large Scale ◽  
Methodological Approach ◽  
Spatial Relationship ◽  
Postal Code ◽  
Annual Income ◽  
Choropleth Maps ◽  
Clustering Approach ◽  
Relationship Of ◽  
Insight Into

This paper describes a methodological approach that is able to analyse socio-demographic and -economic data in large-scale spatial detail. Based on the two variables, population density and annual income, one investigates the spatial relationship of these variables to identify locations of imbalance or disparities assisted by bivariate choropleth maps. The aim is to gain a deeper insight into spatial components of socioeconomic nexuses, such as the relationships between the two variables, especially for high-resolution spatial units. The used methodology is able to assist political decision-making, target group advertising in the field of geo-marketing and for the site searches of new shop locations, as well as further socioeconomic research and urban planning. The developed methodology was tested in a national case study in Germany and is easily transferrable to other countries with comparable datasets. The analysis was carried out utilising data about population density and average annual income linked to spatially referenced polygons of postal codes. These were disaggregated initially via a readapted three-class dasymetric mapping approach and allocated to large-scale city block polygons. Univariate and bivariate choropleth maps generated from the resulting datasets were then used to identify and compare spatial economic disparities for a study area in North Rhine-Westphalia (NRW), Germany. Subsequently, based on these variables, a multivariate clustering approach was conducted for a demonstration area in Dortmund. In the result, it was obvious that the spatially disaggregated data allow more detailed insight into spatial patterns of socioeconomic attributes than the coarser data related to postal code polygons.

Intrasellar Intercarotid Communicating Artery Associated with Agenesis of the Right Internal Carotid Artery: Case Report

Neurosurgery ◽  
1988 ◽  
Vol 23 (6) ◽  
pp. 770-773 ◽  
Author(s):  
Masahiko Udzura ◽  
Hiroo Kobayashi ◽  
Yoshio Taguchi ◽  
Hiroaki Sekino
Keyword(s):  
Magnetic Resonance Imaging ◽  
Carotid Artery ◽  
Internal Carotid Artery ◽  
Internal Carotid ◽  
Spatial Relationship ◽  
Resonance Imaging ◽  
Anomalous Artery ◽  
Magnetic Resonance Imaging Mri ◽  
The Right ◽  
Relationship Of

Abstract A 54-year-old man with a right hemiparesis was found to have an intrasellar intercarotid communicating artery associated with agenesis of the right internal carotid artery. Magnetic resonance imaging (MRI) studies demonstrated the spatial relationship of the anomalous artery to the surrounding structures, thus suggesting an embryonic enlargement of the capsular artery as a source of this anomalous artery.

scholarly journals Design and realization of relic augmented reality system of integration positioning and posture sensing technology

2018 ◽  
Vol 246 ◽  
pp. 03014
Author(s):  
Xin Huo ◽  
Hong Chen ◽  
YuHao Ma ◽  
Qing Wang
Keyword(s):  
Augmented Reality ◽  
System Development ◽  
Mobile Terminal ◽  
Virtual Object ◽  
Natural Scenes ◽  
Augmented Reality System ◽  
Sensing Technology ◽  
Development Technology ◽  
Correct Location ◽  
Presentation Effect

On the purpose of presenting the old appearance of the relics through digitalization, and overlapping the virtual scenes with the actual scenes at the relic site, in this paper, we introduced the positioning technology, posture sensing technology and system development technology, put forward constructing cultural relic tourism platform based on integration positioning and posture sensing technology, we conducted detailed research and analysis on the users’ experienced process of cultural tourism, designed a relic augmented reality system of integration positioning and posture sensing technology. This augmented reality system mainly utilizes positioning technology to guide the users to the correct location of the relic on the corresponding map, and then overlaps the virtual object with the real relic, achieveing a 360-degree view of the overlapping effect, and the presentation effect of near-small, far-big. The system mainly employs Unity to develop the system and realize the above system on mobile terminal. It is no longer limited to a fixed point experience environment, and is suitable for outdoor natural scenes, it makes a breakthrough on the traditional overlapping of virtual scenes and real scenes, realizes the precise overlap of virtual 3D scenes with actual images, and enables the users to feel the vicissitudes of history along the movement of the mobile device in outdoor natural scenes, so as to inherit the history and culture, enrich the information and add some fun to the displayed scene, it has the advantages of bringing people more immersive feelings compared with the traditional virtual display platform.

Real-Time Occlusion Between Real and Digital Objects in Augmented Reality

2018 ◽  
Author(s):  
Kevin Lesniak ◽  
Conrad S. Tucker
Keyword(s):  
Augmented Reality ◽  
Coordinate System ◽  
Real Time ◽  
Real World ◽  
Virtual Object ◽  
Virtual Objects ◽  
Common Coordinate System ◽  
Realistic Representation ◽  
Lead Users

The method presented in this work reduces the frequency of virtual objects incorrectly occluding real-world objects in Augmented Reality (AR) applications. Current AR rendering methods cannot properly represent occlusion between real and virtual objects because the objects are not represented in a common coordinate system. These occlusion errors can lead users to have an incorrect perception of the environment around them when using an AR application, namely not knowing a real-world object is present due to a virtual object incorrectly occluding it and incorrect perception of depth or distance by the user due to incorrect occlusions. The authors of this paper present a method that brings both real-world and virtual objects into a common coordinate system so that distant virtual objects do not obscure nearby real-world objects in an AR application. This method captures and processes RGB-D data in real-time, allowing the method to be used in a variety of environments and scenarios. A case study shows the effectiveness and usability of the proposed method to correctly occlude real-world and virtual objects and provide a more realistic representation of the combined real and virtual environments in an AR application. The results of the case study show that the proposed method can detect at least 20 real-world objects with potential to be incorrectly occluded while processing and fixing occlusion errors at least 5 times per second.

scholarly journals Correlation analysis between multifractal characteristics of regional geomorphology and development of geological disasters

2021 ◽  
Vol 25 (1) ◽  
pp. 49-55
Author(s):  
Yiying Xiong
Keyword(s):  
Correlation Analysis ◽  
Spatial Relationship ◽  
Analysis Method ◽  
Self Similarity ◽  
Geological Disasters ◽  
Geological Disaster ◽  
Correlation Analysis Method ◽  
Fractal Spectrum ◽  
Fractal Characteristics ◽  
Relationship Of

In view of the inaccuracy of the traditional correlation analysis method, this paper proposes a correlation analysis method between the multifractal characteristics of regional landforms and the development of geological disasters. Firstly, the multifractal characteristics of regional landforms are described by using the basic fractal characteristics of self-similarity or scale invariance. Then the corresponding relation table is established according to the width of the fractal spectrum and the number of landslides and hidden dangers, and the spatial relationship of geological disaster development is analyzed. Combined with the above-mentioned spatial relationship of geological disaster development and the multifractal characteristic data of regional landforms, the correlation coefficient between the two is calculated to complete the correlation analysis between the multifractal characteristics of regional geomorphology and the development of geological disasters. The experimental results show that compared with the traditional correlation analysis method, the correlation analysis results of the multifractal characteristics of regional geomorphology and the development of geological disasters are more accurate.

scholarly journals Necessidades de informação do Gênero Mulher no Distrito Federal, Brasil: resultado de um survey

2015 ◽  
Vol 13 (2) ◽  
pp. 418
Author(s):  
Rita de Cássia do Vale Caribé ◽  
Alejandra Aguilar Pinto ◽  
Fabiene Castelo Branco Diogenes
Keyword(s):  
Literature Review ◽  
Information Needs ◽  
Qualitative Methodology ◽  
User Studies ◽  
User Needs ◽  
Frequency Of Use ◽  
Information User ◽  
Distrito Federal ◽  
Relationship Of ◽  
The Relationship

Estudo insere-se na área de estudo de usuários, relata os resultados de um survey, realizado no Distrito Federal (DF), Brasil, com o objetivo de identificar as necessidades e o uso de informação pelas mulheres, tendo utilizado uma amostra aleatória de 37 entrevistas estruturadas. Inclui breve revisão de literatura sobre estudos de usuários com o objetivo de identificar as necessidades e uso da informação por diferentes categorias de indivíduos; apresenta a evolução dos estudos de usuários em termos metodológicos e de abordagem quantitativa e qualitativa; e estudos relacionados à necessidade e uso de informação do gênero mulher. Nesta pesquisa foram identificados os graus de importância de alguns temas, as fontes e instrumentos que interessam à mulher do DF e a gradação de freqüência do uso, bem como, analisada a relação dessas fontes de preferência com o perfil de escolaridade, idade e renda.AbstractThis study may be considered an information user needs study. It reports results of a survey conducted in Distrito Federal (DF), Brazil. Its objective was identifying the information needs and use of women, and was used a random sample of 37 interviews structured. Includes brief literature review on user studies with the goal of identifying the needs and use of information by different individuals categories; shows the evolution of user studies of quantitative and qualitative methodology and approach; and the need and use of information from the woman gender studies. In this research the importance degrees of some topics, sources and instruments that are interested to the wife of DF and gradation of frequency of use were identified, were analyzed the relationship of these sources preferably with the profile of education, age and income.KeywordsUser information needs. User studies. Woman gender.AbstractThis study may be considered an information user needs study. It reports results of a survey conducted in Distrito Federal (DF), Brazil. Its objective was identifying the information needs and use of women, and was used a random sample of 37 interviews structured. Includes brief literature review on user studies with the goal of identifying the needs and use of information by different individuals categories; shows the evolution of user studies of quantitative and qualitative methodology and approach; and the need and use of information from the woman gender studies. In this research the importance degrees of some topics, sources and instruments that are interested to the wife of DF and gradation of frequency of use were identified, were analyzed the relationship of these sources preferably with the profile of education, age and income. Keywords User information needs. User studies. Woman gender.

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