Types Of Contours Research Articles

Selection of contour images based on alphabetical representation

The article is devoted to the actual problem of searching for contour images by given reference samples, due to the large amount of graphic scientific and technical information of the Contour type. Existing methods for image search do not allow taking into account the actual identity of images arising from affine transformations (stretching / compression, rotation) resulting from replication, which is important when analyzing graphic documentation. The paper proposes an alphabetical representation of contour images, which made it possible to construct a complex of affine-invariant equivalence relations. The relations built up served as the basis for the development of a set of selection procedures that can be considered as the initial stage of image search. The procedures included in the complex sequentially implement the reduction of the search scope up to a small set of contour images, allowing for the possibility of visual analysis. The complex is programmatically implemented in Python using the CUDA (NVIDIA GPU) software and hardware architecture for parallel computing.

QUANTITATIVE ANALYSIS OF LONGITUDINAL CHANGES IN MULTIMODAL IMAGING OF LATE-ONSET RETINAL DEGENERATION.

To quantitatively analyze clinically relevant features on longitudinal multimodal imaging of late-onset retinal degeneration to characterize disease progression. Fundus autofluorescence (FAF), infrared reflectance, and optical coherence tomography imaging of 4 patients with late-onset retinal degeneration were acquired over 3 to 15 years (20 visits total). Corresponding regions of interest were analyzed on FAF (reticular pseudodrusen [RPD], "speckled FAF," and chorioretinal atrophy) and infrared reflectance (hyporeflective RPD and target RPD) using quantitative measurements, including contour area, distance to fovea, contour overlap, retinal thickness, and texture features. Cross-sectional analysis revealed a moderate correlation (RPD FAF ∩ RPD infrared reflectance = 63%) between contour area across modalities. Quantification of retinal thickness and texture analysis of areas contoured on FAF objectively differentiated the contour types. A longitudinal analysis of aligned images demonstrates that the contoured region of atrophy both encroaches toward the fovea and grows monotonically with a rate of 0.531 mm/year to 1.969 mm/year (square root of area, n = 5 eyes). A retrospective analysis of precursor lesions of atrophy reveals quantifiable progression from RPD to speckled FAF to atrophy. Image analysis of time points before the development of atrophy reveals consistent patterns over time and space in late-onset retinal degeneration that may provide useful outcomes for this and other degenerative retinal diseases.

A Predictive Model to Differentiate Between Second Primary Lung Cancers and Pulmonary Metastasis

To develop and validate a nomogram for differentiating second primary lung cancers (SPLCs) from pulmonary metastases (PMs). A total of 261 lesions from 253 eligible patients were included in this study. Among them, 195 lesions (87 SPLCs and 108 PMs) were used in the training cohort to establish the diagnostic model. Twenty-one clinical or imaging features were used to derive the model. Sixty-six lesions (32 SPLCs and 34 PMs) were included in the validation set. After analysis, age, lesion distribution, type of lesion, air bronchogram, contour, spiculation, and vessel convergence sign were considered to be significant variables for distinguishing SPLCs from PMs. Subsequently, these variables were selected to establish a nomogram. The model showed good distinction in the training set (area under the curve=0.97) and the validation set (area under the curve=0.92). This study found that the nomogram calculated from clinical and radiological characteristics could accurately classify SPLCs and PMs.

Assessing automated CMR contouring algorithms using systematic contour quality scoring analysis

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): SmartHeart EPSRC programme grant (www.nihr.ac.uk), London Medical Imaging and AI Centre for Value-Based Healthcare Background Quality measures for machine learning algorithms include clinical measures such as end-diastolic (ED) and end-systolic (ES) volume, volumetric overlaps such as Dice similarity coefficient and surface distances such as Hausdorff distance. These measures capture differences between manually drawn and automated contours but fail to capture the trust of a clinician to an automatically generated contour. Purpose We propose to directly capture clinicians’ trust in a systematic way. We display manual and automated contours sequentially in random order and ask the clinicians to score the contour quality. We then perform statistical analysis for both sources of contours and stratify results based on contour type. Data The data selected for this experiment came from the National Health Center Singapore. It constitutes CMR scans from 313 patients with diverse pathologies including: healthy, dilated cardiomyopathy (DCM), hypertension (HTN), hypertrophic cardiomyopathy (HCM), ischemic heart disease (IHD), left ventricular non-compaction (LVNC), and myocarditis. Each study contains a short axis (SAX) stack, with ED and ES phases manually annotated. Automated contours are generated for each SAX image for which manual annotation is available. For this, a machine learning algorithm trained at Circle Cardiovascular Imaging Inc. is applied and the resulting predictions are saved to be displayed in the contour quality scoring (CQS) application. Methods: The CQS application displays manual and automated contours in a random order and presents the user an option to assign a contour quality score 1: Unacceptable, 2: Bad, 3: Fair, 4: Good. The UK Biobank standard operating procedure is used for assessing the quality of the contoured images. Quality scores are assigned based on how the contour affects clinical outcomes. However, as images are presented independent of spatiotemporal context, contour quality is assessed based on how well the area of the delineated structure is approximated. Consequently, small contours and small deviations are rarely assigned a quality score of less than 2, as they are not clinically relevant. Special attention is given to the RV-endo contours as often, mostly in basal images, two separate contours appear. In such cases, a score of 3 is given if the two disjoint contours sufficiently encompass the underlying anatomy; otherwise they are scored as 2 or 1. Results A total of 50991 quality scores (24208 manual and 26783 automated) are generated by five expert raters. The mean score for all manual and automated contours are 3.77 ± 0.48 and 3.77 ± 0.52, respectively. The breakdown of mean quality scores by contour type is included in Fig. 1a while the distribution of quality scores for various raters are shown in Fig. 1b. Conclusion We proposed a method of comparing the quality of manual versus automated contouring methods. Results suggest similar statistics in quality scores for both sources of contours. Abstract Figure 1

Impaired perception of illusory contours and cortical hypometabolism in patients with Parkinson’s disease

Neuroimaging evidence suggests that areas of the higher-order visual cortex, including the lateral occipital complex (LOC), are engaged in the perception of illusory contours; however, these findings remain unsubstantiated by human lesion data. Therefore, we assessed the presentation time necessary to perceive two types of illusory contours formed by Kanizsa figures or aligned line ends in patients with Parkinson's disease (PD). Additionally, we used 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) to measure regional cerebral glucose metabolism in PD patients. Although there were no significant differences in the stimulus durations required for perception of illusory contours formed by aligned line ends between PD patients and controls, PD patients required significantly longer stimulus durations for the perception of Kanizsa illusory figures. Difficulty in perceiving Kanizsa illusory figures was correlated with hypometabolism in the higher-order visual cortical areas, including the posterior inferior temporal gyrus. These findings indicate an association between dysfunction in the posterior inferior temporal gyrus, a region corresponding to a portion of the LOC, and impaired perception of Kanizsa illusory figures in PD patients.

The encoding of epistemic operations in two Romance languages: The interplay between intonation and discourse markers

For years, linguists have noted that intonation patterns and discourse markers encode similar pragmatic meanings across languages. The present study investigates whether a functional compensatory distribution can be documented across languages by focusing on the expression of epistemic commitment in two Romance languages which have been reported to have either a rich or a very reduced inventory of intonational patterns (e.g., Catalan vs. Friulian). A total of 30 speakers (15 per language) participated in an oral Discourse Completion Task designed to elicit assertions with three degrees of speaker commitment. The results showed that while Catalan used specific intonation patterns for the expression of low and intensified commitment statements, Friulian speakers used only one type of pitch contour to express both types of epistemic commitment. In contrast, Friulian speakers made more frequent use of a more varied set of epistemic discourse markers for the two types of biased statements than their Catalan-speaking peers. This result suggests that a trade-off strategy can be observed between intonation and discourse markers across these two languages. This ultimately shows the need to integrate the study of intonational meaning with other parts of the grammar inside a more unified approach in comparative analyses of language.

Contours produced by internal specular interreflections provide visual information for the perception of glass materials.

Two experiments are reported that investigated how the perceptual identification of glass is influenced by banding contours formed by internal specular interreflections within glass materials. Observers made material categorization judgments for images depicting glass, chrome, shiny black and shiny white objects, and for contour drawings that were created by edge filtering images of glass, chrome or textured objects. Observers rated each stimulus by adjusting four sliders to indicate their confidence that the depicted material was glass, metal, shiny black, or something else, and these adjustments were constrained so that the sum of all four settings was always 100%. The results revealed that the rendered images were all categorized correctly with a high level of confidence. The contour drawings of glass and textured materials were also categorized correctly with a high level of confidence. However, the contour drawings of chrome materials were miscategorized as glass, with an average confidence rating that was significantly lower than those obtained for the glass contours. It is hypothesized that these different contour types are perceptually distinguished from one another based on how they align with the pattern of surface curvature on an object and the smoothness of the contours.

The moment-to-moment pitch dynamics of child-directed speech shape toddlers' attention and learning.

Young children have an overall preference for child-directed speech (CDS) over adult-directed speech (ADS), and its structural features are thought to facilitate language learning. Many studies have supported these findings, but less is known about processing of CDS at short, sub-second timescales. How do the moment-to-moment dynamics of CDS influence young children's attention and learning? In Study 1, we used hierarchical clustering to characterize patterns of pitch variability in a natural CDS corpus, which uncovered four main word-level contour shapes: 'fall', 'rise', 'hill', and 'valley'. In Study 2, we adapted a measure from adult attention research-pupil size synchrony-to quantify real-time attention to speech across participants, and found that toddlers showed higher synchrony to the dynamics of CDS than to ADS. Importantly, there were consistent differences in toddlers' attention when listening to the four word-level contour types. In Study 3, we found that pupil size synchrony during exposure to novel words predicted toddlers' learning at test. This suggests that the dynamics of pitch in CDS not only shape toddlers' attention but guide their learning of new words. By revealing a physiological response to the real-time dynamics of CDS, this investigation yields a new sub-second framework for understanding young children's engagement with one of the most important signals in their environment.

Morphological Classification of the Zygomatic Regions in Young Chinese Han Males and Females Based on a Simulated Moiré Pattern.

The complex curved contours of the zygomatic regions are difficult to analyze. Therefore, a better evaluation medium must be developed. We aimed to examine and summarize the morphological characteristics of the zygomatic region by using a moiré pattern map and computer algorithm. In this cross-sectional study, we collected three-dimensional images of the facial contours of 251 Han Chinese youth and established a morphological moiré map database. Clustering analysis using a computer algorithm was applied to obtain the zygomatic morphologies for classification. Aesthetic evaluation was performed to summarize the characteristics of the zygomatic types and provide reference for the preoperative morphological design of the midface. Zygomatic regions were morphologically classified into five types. Each type had its typical feature in the moiré pattern map. The moiré stripes in the left zygomatic region formed an "Ω" shape outward and downward in type 1, and they tended to be diagonal like "\\\" in type 2, smoothly curved like ")))" in type 3, vertical like "|||" in type 4, and diagonal like "///" in type 5. The aesthetic evaluation outcome indicated that the integrally flat zygoma (type 4) was more aesthetically pleasing among males, and the integrally prominent zygoma (type 3) was more aesthetically pleasing among females. Five morphological contour types of the zygoma were classified among the Chinese Han males and females based on the simulated moiré pattern. This morphological classification would aid in preparing a guide for clinical diagnosis and surgical planning.

Classification and Treatment of Glabella-Radix Deficiency in Primary Augmentation Rhinoplasty.

BackgroundA systematic approach to treating glabella-radix deficiency is lacking, and the management of brow-tip aesthetic lines remains technically challenging.ObjectivesThe authors describe implantation of a customized Gore-Tex prosthesis combined with primary augmentation rhinoplasty to address the glabella-radix deficiency.MethodsFifty Asian patients with glabella-radix deficiency who received implantation and primary augmentation rhinoplasty were retrospectively evaluated in an 8-year period. Patients were assigned to categories based on brow-tip contour lines and symmetry patterns, and implant dimensions were ascertained from the contour type and from simulated postoperative results.ResultsEleven men and 39 women were included in the study; the mean patient age was 27.22 years, and mean follow-up was 22.8 months. Seven of the patients were assigned to the type I/Ia category, 24 to type II/IIa, and 19 to type III/IIIa. Forty-five patients were considered to have satisfactory surgical results, with curved, symmetric, and normally spaced brow-tip lines on front view and a smooth frontonasal transition on profile view. Complications occurred in 5 patients and included infection (1 patient), inadequate augmentation (2), and palpable margin folding of the Gore-Tex device (2).ConclusionsDeformities of brow-tip contour lines coincide with glabella-radix deficiencies in terms of severity. Knowledge of the patterns of brow-tip lines, combined with postoperative image simulation, can help the surgeon design an appropriate glabella-radix prosthesis. When placed in conjunction with other augmentation rhinoplasty procedures, the glabella-radix implant yields sufficient, predictable nasal projection and a harmonious facial aesthetic.Level of Evidence: 4

Prosody and grammar of other-repetitions in French: The interplay of position and composition

ABSTRACTThis study contributes to the body of cross-linguistic research on repetition, repair, and action-formation more generally. Using conversation-analytic and interactional-linguistic methods to analyse both position and composition in the formation of actions accomplished by other-repetitions in French, the study underscores the interplay between linguistic design, sequential organisation, and territories of knowledge and accountability in interaction. The actions conveyed by other-repetitions, and the responses made relevant, are affected by both (i) the design of the repetition turn itself—involving various features of prosody (e.g. intonation contour type and pitch span), grammar, and lexis—and (ii) the sequential location of the repetition, including the particulars of the talk that gets repeated and the relevancies set up by that previous talk. The study concludes with a discussion of its significance for research on action-formation as well as for research on the pragmatics of intonation. (Repair-initiation, surprise, acceptability, registering, intonation, epistemics, agency)*

Intelligent detection of edge inconsistency for mechanical workpiece by machine vision with deep learning and variable geometry model

Inconsistent edges of mechanical workpieces in the same batch are one of the main reasons that lead to different machining performance. A full recognition of the inconsistent features has significant impact on enhancement of their intelligent machining ability. An intelligent hybrid strategy is proposed for edge inconsistent feature detection by machine vision, in which deep learning is combined with variable geometric model together to conduct the function. A deep convolutional neural network based feature classification model is established with K-Means clustering tactic. Supported on the classification model, a variable geometric model for specific edge inconsistency is given with an inconsistency evaluation function to investigate the match degree between the geometric model and the actual detected edge, and then particle swarm optimization algorithm is applied to find the solution of this geometric model. Detection experiments are carried out on a domestic servo-driven vision measuring platform to verify the performance of the proposed approach. The results show that the combined scheme can classify the different type of geometric contour of edge features with 100% correctness, and better evaluation performance by dice similarity index and Hausdorff distance in comparisons with other recent candidate methodologies. It is also indicated that the presented method provides a good recognition of the geometrical shape with less than 0.06mm maximum error for workpiece with 142 × 119mm size in the visual field.

浅谈广东省公路隧道岩爆段内轮廓型式及隧道净距的选择

浅谈广东省公路隧道岩爆段内轮廓型式及隧道净距的选择

Using critical curves to compute master stability islands for amplitude death in networks of delay-coupled oscillators.

In this paper, we present a method to compute master stability islands (MSIs) for amplitude death in networks of delay-coupled oscillators using critical curves. We first demonstrate how critical curves can be used to compute boundaries and contours of MSIs in delay-coupling parameter space and then provide a general study on the effects of the oscillator dynamics and network topology on the number, size, and contour types of all MSIs. We find that the oscillator dynamics can be used to determine the number and size of MSIs and that there are six possible contour types that depend on the choice of oscillator dynamics and the network topology. We introduce contour sequences and use these sequences to study the contours of all MSIs. Finally, we provide example MSIs for several classical nonlinear systems including the van der Pol system, the Rucklidge system, and the Rössler system.

New Contour Design Method for Rocket Nozzle of Large Area Ratio

A rocket engine for space propulsion usually has a nozzle of a large exit area ratio. The nozzle efficiency is greatly affected by the nozzle contour. This paper analysed the effect of the constant capacity ratio in Rao’s method through the design process of an apogee engine. The calculation results show that increasing the heat capacity ratio can produce an expansion contour of smaller expansion angle and exit area ratio. A simple modification of Rao’s method based on thermally perfect gas assumption was made and verified to be more effective. The expansion contour designed by this method has much thinner expansion section and higher performance. For the space engine, a new extension contour type for the end section of the nozzle is proposed. The extension curve bent outward with increasing expansion angle increases the vacuum specific impulse obviously.

Implicit effects of regional cues on the interpretation of intonation by Corsican French listeners

It is now well documented for different varieties of English that the speech production and perception systems rapidly adapt to contextual social cues. This adaptation is sensitive not only to speaker social identity but also to implicit social cues, suggesting that the underlying mechanism is automatic rather than controlled. While it has recently been shown that the interpretation of intonation depends on segmental cues to sociolect within the same utterance, the present study explores whether it also depends on implicit contextual social cues. Starting from the observation that a specific type of intonational contour is used differently in Corsican French and Continental French, we tested whether Corsican French listeners interpret this contour differently depending on which dialectal region is evoked by a visual cue. The results are consistent with this hypothesis, thus providing evidence for implicit social adaption in a new domain of linguistic behavior, specifically, the prosody-meaning interface. We describe an exemplar-based model of our results demonstrating that such models can be readily extended to capture the effects found by the present study.

An experimental and analytical investigation of canyon fire spread

This work investigates the fire line evolution in canyon fire spread by analytical and experimental means. The purpose is to understand the mechanism of fire spread acceleration associated with eruptive fire in canyon terrain. A symmetrical model canyon is used for experiments, and in each test the fire is initiated by a point ignition using dead pine needles as the fuels. By experimental observations and data, three distinct types of fire line contour are identified under different central slope angles (the angle between the canyon centerline and the horizontal ground), resulting in different variation modes of rate of spread along the canyon centerline. It is found that the trace of fire head deviates from the line of maximum slope for non-zero central slope angles, and such a deviation increases with increasing central slope angle. The fire spread acceleration associated with eruptive fire occurs when the central slope angle reaches a certain critical value. Experimental data confirm that under higher slope conditions, the significant interaction between the two lateral flame fronts induces marked convective heating ahead of the flame front, which is inferred to be the potential mechanisms of eruptive fire in canyon topography. A model analysis further elucidates how the deflection of the trace of fire head, induced by the fire interaction effect, influences the acceleration of fire spread under higher slope conditions.

Technical Note: Quality assurance of proton central axis pencil‐beam spread‐out Bragg peak using large‐diameter multilayer ionization chambers

The aim of this work is to describe a method of machine quality assurance (QA) by measuring proton spread-out Bragg peak constructed by the integrated depth dose via a large-diameter (12-cm) multilayer ionization chamber (LD-MLIC). Two types of contours are used to create the nominal plan. The final nominal plan is composed of mixed-energy proton pencil-beam spots located close to the central axis. The integrated depth dose (IDD) curve contains a flat SOBP region. The LD-MLIC-measured IDD was compared to the IDD curve exported from the treatment planning system (TPS). In addition, three plans with intentionally modified energy layers to simulate wrong-delivered energy layers were created and measured by the LD-MLIC. The water equivalent thickness (WET) difference between the inserted and replaced energies was 0.2cm. Six weeks of measurements were analyzed. A low-pass filter was introduced to mitigate the high-frequency noise in the IDD signal ratios. The filtered IDD signal ratios between the modified plans in different weeks and the baseline were used to check the energy accuracy. The differences between the LD-MLIC-measured and TPS-exported IDDs of the nominal plan were within 2% in most parts of the curve. Bumps/dips (~1%) were noted in the filtered IDD ratio between the modified plans and the baseline. The LD-MLIC can be used to check the accuracy of multiple energies Bragg peak locations quickly in proton machine QA. The LD-MLIC was sensitive in identifying an erroneous energy with 0.2cm in WET.

An Extension of the Minimally Divergent Contour Network: Considering Nonconsecutive Repeated Contour Pitches

Abstract In a 2013 article, I partitioned all musical contours into fifteen types and arranged them in a network called the minimally divergent contour network (MDCN). Within the MDCN, we can examine the similarity between any two contour types by measuring the shortest path between them. However, despite the methodological efficiency, none of the fifteen types considers nonconsecutive repeated contour pitches. Prompted by this issue, this article extends the MDCN to include nonconsecutive repeated contour pitches. To demonstrate the analytic utility of the extended MDCN, I examine works by Bright Sheng and György Kurtág.

T1a renal cell carcinoma on unenhanced CT: analysis of detectability and imaging features.

BackgroundIncreasing use of unenhanced computed tomography (CT) has been associated with the increasing incidental detection of renal cell carcinoma (RCC) at an earlier stage.PurposeTo evaluate the characteristics in detecting and differentiating T1a RCCs on unenhanced CT.Material and MethodsWe retrospectively reviewed 68 patients with 68 T1a RCCs and 39 benign regions. Two radiologists interpreted the images on unenhanced axial CT and performed a blinded and independent review of T1a RCCs. The readers evaluated the presence of RCC and differentiated the detected lesions.ResultsThe consensus of two readers detected 53 (78%) RCCs. Of the 53 detected RCCs, 42 (62%) RCCs were correctly diagnosed and 11 (16%) masses were misdiagnosed as benign. Of the 39 benign regions, 29 (74%) cysts were diagnosed correctly, but 10 (26%) cysts were misdiagnosed as malignant. The following values of the radiologists were obtained by consensus: sensitivity = 61.8% (42/68); specificity = 74.4% (29/39); positive predictive value = 80.8% (42/52); negative predictive value = 55.0% (29/55); accuracy = 66.4% (71/107). The receiver operating characteristic curve of consensus was 0.754. Inter-observer correlation was κ = 0.849. There was a significant difference in tumor size (P = 0.019) and the contour type of tumor (P = 0.0207) between correctly diagnosed RCCs and not correctly diagnosed RCCs.ConclusionOur findings showed that tumor size and contour type could affect the detection and differentiation of T1a RCC on unenhanced CT. To detect and differentiate T1a RCC on unenhanced CT is difficult. However, the findings from this study may help detection of RCCs on unenhanced CT.