Stereograms to aid group recognition and trend identification in vegetation data

1978 ◽  
Vol 56 (2) ◽  
pp. 162-165 ◽  
Author(s):  
P. Fewster ◽  
L. Orlóci
Keyword(s):  
Three Dimensional ◽  
Three Dimensions ◽  
Simple Method ◽  
Sample Points ◽  
Left Image ◽  
Dimensional Object ◽  
The Right ◽  
Trend Identification ◽  
Dimensional Picture

When vegetation data are summarized on the basis of some method of ordination, a search for distinct groups or trends is greatly facilitated if the cloud of sample points is viewed under a lens stereoscope in three dimensions. The present paper describes a simple method to construct stereograms and illustrates their application in a classification problem.A stereogram is composed of two images of a three-dimensional object. The left image and the right correspond respectively to sightings with the left eye or the right eye of the observer. The diagrams are placed side by side at a specified distance apart, and when viewed with the aid of a stereoscope, the images will merge resulting in a three-dimensional picture.

The three-dimensional stable mandibular landmarks in patients between the ages of 12.5 to 17.1 years

2020 ◽  
Author(s):  
Gui Chen ◽  
Mona Al Awadi ◽  
David William Chambers ◽  
Manuel O Lagravère-Vich ◽  
Tianmin Xu ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Growth Period ◽  
Mandibular Canal ◽  
Mental Foramen ◽  
Three Dimensions ◽  
Head Orientation ◽  
Facial Growth ◽  
Linear Distance ◽  
The Right ◽  
Stable Structures

Abstract Background: With the aid of implants, Björk identified the two-dimensional mandibular stable structures in cephalogram during facial growth. However, we don't know the three-dimensional stable structures exactly. The purpose of this study was to identify the most stable mandibular landmarks in growing patients using three-dimensional images.Methods: The sample was comprised of two cone-beam computed tomography (CBCT) scans taken about 4.6 years apart in 20 growing patients between the ages of 12.5 (T1) to 17.1 years (T2). After head orientation, landmarks were located on the chin (Pog), internal symphysis (Points C, D and E), and mandibular canals, which included the mental foramina (MF and MFA) and mandibular foramina (MdF). The linear distance change between Point C and these landmarks was measured on each CBCT to test stability through time. The reliability of the suggested stable landmarks was also evaluated. Results: The total distance changes between Point C and points D, E, Pog, MF, and MFA were all less than 1.0 mm from T1 to T2. The reliability measures of these landmarks, which were measured by the Cronbach alpha, were above 0.94 in all three dimensions for each landmark. From T1 to T2, distance changes from Point C to the right and left mandibular foramina were respectively 3.39±3.29 mm and 3.03±2.83 mm. Conclusions: During a growth period that averaged 4.6-years, ranging from 11.2 to 19.8 years, the structures that appeared relatively stable and could be used in mandibular regional superimposition included Pog, landmarks on the inferior part of the internal symphysis, and the mental foramen. The centers of the mandibular foramina, the starting points of the mandibular canal, underwent significant changes in the transverse and sagittal dimensions.

Extrapolating and interpolating surfaces in depth

1985 ◽  
Vol 224 (1234) ◽  
pp. 43-56 ◽  
Keyword(s):  
Three Dimensional ◽  
Surface Orientation ◽  
Three Dimensions ◽  
Apparent Depth ◽  
Right Hand ◽  
Pictorial Cues ◽  
Random Dot Stereograms ◽  
Sloping Surface ◽  
The Right ◽  
Hand Image

Random -dot stereograms were generated with a blank area placed in part of the right-hand image so making a patchwork of monocular and binocular areas. The perceived depth and shape of the monocular region, where depth was not explicitly marked, depended in p art on the depth and surface orientation of adjacent binocular areas. Thus a monocular rectangle flanked by two binocular rectangles which were placed in different fronto-parallel planes was seen as a sloping surface spanning the depth between the binocular regions, and, under some conditions, the gradient of a sloping binocular plane extended into a neighbouring monocular area. Division of the monocular region into two by textural discontinuities or discontinuities of motion sometimes altered the shape of the extrapolated surface. Often, though, the shape was unchanged by such discontinuities implying that both two- and three-dimensional features are used to segment a scene into separate surfaces. Pictorial cues also contribute to the shape and apparent depth of the monocular surface. For instance, when subjects viewed a display consisting of portions of a cube of which two ends were shown stereoscopically and one side monocularly, the monocular side was seen in three dimensions filling the gap between the ends. When stereo cues were pitted against pictorial cues, sometimes pictorial cues and sometimes stereo cues dominated, and sometimes the surface contained sharp discontinuities enabling both to be accommodated.

An asymptotic theory of the jet flap in three dimensions

1971 ◽  
Vol 46 (4) ◽  
pp. 705-726 ◽  
Author(s):  
Naoyuki Tokuda
Keyword(s):  
Order Approximation ◽  
Three Dimensional ◽  
Outer Region ◽  
Two Dimensions ◽  
Three Dimensions ◽  
Simple Method ◽  
Aspect Ratios ◽  
Line Theory ◽  
Lifting Line ◽  
Lifting Line Theory

A uniformly valid asymptotic solution has been constructed for three-dimensional jet-flapped wings by the method of matched asymptotic expansions for high aspect ratios. The analysis assumes that the flow is inviscid and incompressible and is formulated on the thin airfoil theory in accordance with the well-established Spence (1961) theory in two dimensions.A simple method emerges in treating the bound vortices along the jet sheet which forms behind the wing with the aid of the following physical picture. Three distinct flow regions—namely inner, outer and Trefitz—exist in the problem. Close to the wing the flow approximates to that in two dimensions. Therefore, Spence's solution in two dimensions applies. In the outer region a wing shrinks to a line of singularities from which the main disturbances of flow in this region arise. In particular, we find that the shape of the jet sheet, hence the strength of vortices, is now predetermined by the strength of the singularities there. Hence a complete flow field in the outer region can now be determined first by evaluating the flow due to various degrees of singularities along this line and then adding the effect of the jet bound vortices which is now known. Far removed from the wing, the well-known Trefftz region exists in which calculations of aerodynamic forces can be most easily done.The result has been applied to various wing planforms such as cusped, elliptic and rectangular wings. The present result breaks down for rectangular wings. However, we can apply Stewartson's (1960) solution for lifting-line theory for semi-infinite rectangular wings, because, to this second-order approximation it is established that the jet sheet in the outer region makes no contribution to lift, with the direct contribution of the deflected jet at the exit being cancelled by the reduced circulation in the jet vortices. This result for the rectangular wing gives excellent agreement with the experiments made on a rectangular wing, while the result for elliptic wings underestimates them considerably.

Measurement of Skier-Generated Forces during Roller-Ski Skating

1995 ◽  
Vol 11 (3) ◽  
pp. 245-256 ◽  
Author(s):  
Glenn M. Street ◽  
Edward C. Frederick
Keyword(s):  
Force Measurement ◽  
Three Dimensional ◽  
Axial Loading ◽  
Three Dimensions ◽  
Calibration Data ◽  
Force Transducers ◽  
Sample Data ◽  
Reaction Forces ◽  
The Right ◽  
Force Measurement System

This paper describes a system that was developed to measure ski pole and roller-ski reaction forces in three dimensions during roller-ski skating. Uni-axial force transducers mounted in the right and left ski poles measure axial loading of the poles. Six transducers in one roller-ski measure biaxial loads beneath the foot. A remote computer stores the amplified transducer signals transmitted from the skier through 100 m cables. Three-dimensional video-graphy determines the orientations of the poles and roller-ski in order to resolve the resultant poling and skating forces into three components. Calibration data suggest that the resolution of the force measurement system is ±3 to 9% of the actual poling and skating forces, respectively. Sample data are presented from a VI skating trial during roller-skiing. These data provide the first glimpse at the major functions of the upper and lower body during roller-ski skating and show how the tool could be used to examine the size and effectiveness of skier-generated forces.

High-Precision 3D Modeling Method Based on Terrestrial Image Sequences for Alpine-Gorge Area

2012 ◽  
Vol 182-183 ◽  
pp. 1270-1275 ◽  
Author(s):  
Bo Su ◽  
Hao Li ◽  
Ya Qin Wang ◽  
Biao Yang
Keyword(s):  
Stereo Matching ◽  
Three Dimensional ◽  
Digital Camera ◽  
Image Sequences ◽  
Three Dimensional Modeling ◽  
Modeling Process ◽  
Dimensional Modeling ◽  
Left Image ◽  
The Right ◽  
Seed Points

The traditional measurement methods cannot adapt to the arduous topography of alpine-gorge area. Aiming at the topographical features of alpine-gorge area, we will introduce a general terrestrial method of multi-baseline photogrammetry basing on digital camera here, and then the paper mainly studies the metrization method of common digital camera and matching method of the digital image sequences of alpine-gorge area. Through the metrization of common digital camera, the efficiency of terrain data collection will increase in the alpine-gorge area, and the requirements of operations on the image control and algorithm will reduce. The combination of seed points and multiple constraints in multi-baseline stereo matching will help to solve many problems, such as shading, severe distortion between the left image and the right one, and the inconformity of scale. The modeling process stated above is quite fast and highly precise, and the three-dimensional modeling experiments show that the relative accuracy can reach from 1 / 8000 to 1 / 12000.

scholarly journals Postoperative volume increase of facial soft tissue after percutaneous versus endonasal osteotomy technique in rhinoplasty using 3D stereophotogrammetry

2011 ◽  
Vol 49 (1) ◽  
pp. 121-126
Author(s):  
B. van Loon ◽  
N. van Heerbeek ◽  
T.J.J. Maal ◽  
W.A. Borstlap ◽  
K.J.A.O. Ingels ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Three Dimensional ◽  
Measurement Data ◽  
Three Dimensions ◽  
Rank Test ◽  
Facial Soft Tissue ◽  
Osteotomy Technique ◽  
3D Stereophotogrammetry ◽  
Soft Tissue Changes ◽  
The Right

BACKGROUND: When lateral osteotomies are performed as part of a rhinoplasty, the nose and paranasal region invariably change in three dimensions. The PURPOSE of this study is to compare the effect of the percutaneous perforating and endonasal continuous osteotomy techniques concerning the degree of postoperative swelling using three dimensional (3D) stereophotogrammetry. METHODOLOGY: A prospective follow-up study was conducted. Patients requiring bilateral osteotomies were included and randomly underwent a percutaneous osteotomy on one side and an endonasal osteotomy on the other side. Pre- and postoperative 3D photos were acquired using 3D stereophotogrammetry. Volumetric measurement data were acquired from the paranasal region using 3D software. Measurements were compared using Student`s t-test and Wilcoxon signed rank test statistics. RESULTS: Twenty patients were included. A percutaneous osteotomy was performed on the right side in nine patients and on the left side in 11 patients. The total volume, the volume of the right paranasal and left paranasal region were significantly larger postoperative. No difference was found between the sides. CONCLUSIONS: No difference concerning swelling is found between the percutaneous and endonasal osteotomy technique sides. With 3D stereophotogrammetry volumetric data can be acquired and compared to evaluate soft-tissue changes.

scholarly journals PENGEMBANGAN MEDIA VIDEO PEMBELAJARAN PENGHANTAR LISTRIK DILENGKAPI OBJEK TIGA DIMENSI PADA MATA KULIAH KABEL DAN TEKNIK PEMASANGANNYA DI PROGRAM STUDI PENDIDIKAN TEKNIK ELEKTRO UNIVERSITAS PENDIDIKAN GANESHA

2019 ◽  
Vol 8 (1) ◽  
Author(s):  
Gede Setiadarma ◽  
Agus Adiarta ◽  
Nyoman Santiyadnya
Keyword(s):  
Three Dimensional ◽  
Field Trials ◽  
Learning Objects ◽  
Three Dimensions ◽  
Instructional Video ◽  
Three Dimensional Objects ◽  
Media Learning ◽  
Dimensional Object ◽  
Electrical Conductors ◽  
Group Trial

Research development aims to: 1) create a media instructional videos electrically conductive include three-dimensional objects, 2) determine the feasibility of video media learning electrical conductors include three-dimensional object, 3) determine the response of students to use video media learning electrical conductors include three-dimensional object. This research is a study of R & D to adapt the pace of development of Sugiyono development model. Media that was developed in the validation by experts and expert media content. Calculation of instruments to the experts and field trials using a scale Linkert. The results of this study in the form of video media products and media learning objects in three dimensions. The results of the percentage gain media expert feasibility level by 98, 67% with a very decent qualifications and earn a percentage of content expert feasibility level of 100% with a very decent qualifications. Results of a small study group trial amounted to 91.27% (excellent qualifications) and a large group trial that shows a student's response amounted to 93.72% (excellent qualifications). So media instructional video and three-dimensional objects that are developed feasible in the subject of wiring and installation techniques for the third semester students of Electrical Engineering Education Program Undiksha.

scholarly journals Cognitive abilities of horses in terms of visual and olfactory perception

2017 ◽  
Vol 73 (1) ◽  
pp. 48-52 ◽  
Author(s):  
Tomasz Próchniak ◽  
Iwona Rozempolska-Rucińska ◽  
Monika Petrykowska ◽  
Grzegorz Zięba ◽  
Brygida Ślaska ◽  
...  
Keyword(s):  
Visual Stimulus ◽  
Cognitive Abilities ◽  
Three Dimensional ◽  
Negative Reaction ◽  
Olfactory Perception ◽  
Two Dimensional ◽  
Object A ◽  
The One ◽  
Dimensional Object ◽  
The Right

The aim of the study was to assess the cognitive abilities of horses in recognizing humans by sight and smell. Two experiments were performed. In the first experiment, the behaviour of horses exposed to a visual stimulus (photographs of familiar and unfamiliar people) was observed. The second experiment examined their behaviour evoked by an olfactory stimulus. The following variables was assessed: the duration of approach to the object in seconds (s), interest in the object, a negative reaction, the duration of the observation of the object (s), the duration of looking with the left eye and the right eye (s), and other signs of interest, e.g. licking, grasping with lips, and touching the object. It was found that the horses were able to identify the human by transferring the identification of a three-dimensional object (a person that positively conditioned the horse) to a two-dimensional object (a photograph of that person’s face). It was also shown that the horses used the sense of smell in associating clothes with the person wearing them (the one who positively conditioned the horse). It was found that positively conditioned horses reacted more strongly to the smell of human clothes than to a photograph of the human.

scholarly journals Measurement of curvature and twist of microtubule bundles in the mitotic spindle

2021 ◽  
Author(s):  
Arian Ivec ◽  
Monika Trupinić ◽  
Iva M. Tolić ◽  
Nenad Pavin
Keyword(s):  
Mitotic Spindle ◽  
Spatial Organization ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Robust Method ◽  
Geometric Information ◽  
Simple Method ◽  
Information Characteristic ◽  
Reproducible Method ◽  
Curved Paths

AbstractThe highly ordered spatial organization of microtubule bundles in the mitotic spindle is crucial for its proper functioning. The recent discovery of twisted shapes of microtubule bundles and spindle chirality suggests that the bundles extend along curved paths in three dimensions, rather than being confined to a plane. This in turn implies that rotational forces exist in the spindle in addition to the widely studied linear forces. However, studies of spindle architecture and forces are impeded by a lack of a robust method for the geometric quantification of microtubule bundles in the spindle. In this paper, we describe a simple method for measuring and evaluating the shapes of microtubule bundles, by characterizing them in terms of their curvature and twist. By using confocal microscopy, we obtain three-dimensional images of spindles, which allow us to trace the entire microtubule bundles. For each traced bundle, we first fit a plane, and then fit a circle lying in that plane. With this easily reproducible method, we extract the curvature and twist, which represent the geometric information characteristic for each bundle. As the bundle shapes reflect the forces within them, this method is valuable for the understanding of forces that act on chromosomes during mitosis.

Nasal Morphology and Shape Parameters as Predictors of Nasal Esthetics in Individuals with Complete Unilateral Cleft Lip and Palate

2001 ◽  
Vol 38 (5) ◽  
pp. 476-485 ◽  
Author(s):  
K. A. Russell ◽  
S. D. Waldman ◽  
B. Tompson ◽  
J. M. Lee
Keyword(s):  
Cleft Lip ◽  
Cleft Lip And Palate ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Entire Group ◽  
Shape Parameters ◽  
Entire Sample ◽  
Sample Group ◽  
Lateral Offset ◽  
The Right

Objective: The purpose of this study was to assess the ability of shape parameters of nasal morphology to predict esthetics in individuals with complete unilateral cleft lip and palate (CUCLP). Methods: This retrospective study involved 28 patients with repaired CUCLP. Nostril morphology was analyzed using nose casts and a video-imaging technique. Calculated shape parameters included area, perimeter, centroid, angle of the principal axis, major and minor moments of area, anisometry, bulkiness, lateral offset, and three-dimensional internostril angles. Esthetics was assessed using a panel of six orthodontists who rated nasal esthetics from frontal, lateral, basal, and three-quarters view slides and from nose casts. Correlations between esthetics and the shape parameters were completed using the entire group as well as using two statistically determined subsets: those with the best and those with the worst esthetics. Results: Nasal esthetics was related to only the perimeter and bulkiness parameter ratios. Symmetry of the perimeters between the right and left nostrils positively correlated with better esthetics using the entire sample group while symmetry of bulkiness between the right and left nostrils positively correlated with better esthetics using both the entire sample group and the best and worst subsets. Conclusions: Only perimeter and bulkiness showed positive correlations with nasal esthetics. The group of parameters used to assess nostril morphology had neither significant correlation with—nor predictive power for—esthetics. Thus, an assessment of the entire nasal surface topography in three dimensions needs to be completed and assessed with respect to predictability of nasal esthetics.

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