Dilation Factor Research Articles

Hierarchical Temporal Modeling With Mutual Distance Matching for Video Based Person Re-Identification

Comparing to image-based person re-identification (re-ID) problems, video-based person re-ID can take advantage of more cues from appearance and temporal information, and therefore receives widespread attention recently. However, due to the different pose, occlusion, misalignment and multi-granularity in video sequences, those consequent inter-sequence variations and intra-sequence variations, inevitably makes the feature learning and matching in videos more difficult. Under this circumstance, it is necessary to design an effective discriminative representation learning mechanism, as well as a matching solution, to tackle these variations in video-based person re-ID. To this end, this paper introduces a multi-granularity temporal convolution network and a mutual distance matching measurement, aiming at alleviating the intra-sequence variation and the inter-sequence variation, respectively. Particularly, in the feature learning stage, we model different temporal granularities by hierarchically stacking temporal convolution blocks with different dilation factors. In the feature matching stage, we propose a clip-level probe-gallery mutual distance measurement and consider the most convincing clip pairs by top-k selection. We validate that our proposed method can achieve state-of-the-art results on three video-based person re-ID benchmarks, more than that, we conduct extensive ablation study to demonstrate conciseness and effectiveness of our method in video re-ID tasks.

Cubic Graphs, Their Ehrhart Quasi-Polynomials, and a Scissors Congruence Phenomenon

The scissors congruence conjecture for the unimodular group is an analogue of Hilbert’s third problem, for the equidecomposability of polytopes. Liu and Osserman studied the Ehrhart quasi-polynomials of polytopes naturally associated to graphs whose vertices have degree one or three. In this paper, we prove the scissors congruence conjecture, posed by Haase and McAllister, for this class of polytopes. The key ingredient in the proofs is the nearest neighbor interchange (NNI) move on graphs and a naturally arising piecewise unimodular transformation. We provide a generalization of the context in which the NNI moves appear, to connected graphs with the same degree sequence. We also show that, up to a dilation factor of 4 and an integer translation, all of these Liu–Osserman polytopes are reflexive.

Optimal use of biologics with endoscopic balloon dilatation for repeated intestinal strictures in Crohn's disease.

Background and AimIntestinal strictures in Crohn's disease (CD) have a high rate of repeated surgery. As alternatives to surgery, endoscopic balloon dilatation (EBD), immunomodulators (IMs), and antitumor necrosis factor alpha (anti‐TNFα) have been proposed. We aimed to assess the effectiveness of the combined therapy with anti‐TNFα and EBD in preventing intestinal stricture recurrence and surgery in patients with CD.MethodsThis retrospective cohort study included patients from the nationwide administrative database in Japan who were hospitalized and underwent at least one EBD between 1 April 2010 and 31 March 2017. The effectiveness of anti‐TNFα was evaluated by performing survival analysis for the primary outcome. We selected the inverse probability of treatment weighting method for adjustment of covariates. As an exploratory analysis, we evaluated the association of anti‐TNFα initiation timing with intestinal stricture recurrence.ResultsThe anti‐TNFα exposed group had a significantly lower risk of intestinal stricture recurrence than that of the anti‐TNFα nonexposed group (hazard ratio = 0.38, 95% confidence interval 0.31–0.48, P < 0.001). Surgery‐free rate was shown to have the same tendency. Anti‐TNFα therapy initiation before or after EBD resulted in a lower risk of intestinal stricture recurrence than that of simultaneous treatment.ConclusionThe combined therapy with anti‐TNFα and EBD could have preventive effects for intestinal stricture recurrence and surgery in hospitalized patients with CD. In particular, anti‐TNFα initiation may be recommended before or after EBD, not immediately after EBD. With respect to EBD, it is important to clarify the effectiveness of combination therapy with several new medication treatments, such as biologics.

Progresión y predictores de insuficiencia valvular neoaórtica y dilatación de la raíz neoaórtica en adultos jóvenes tras cirugía de switch arterial

Introduction and objectivesThere are limited data on the long-term development of neoaortic root dilatation (NRD) and neoaortic valve regurgitation (AR) after arterial switch operation (ASO) for transposition of the great arteries during adult life. MethodsWe performed a retrospective longitudinal analysis of 152 patients older than 15 years who underwent ASO for transposition of the great arteries and who were followed-up for 4.9±3.3 years in 2 referral centers. Sequential changes in body surface-adjusted aortic root dimensions and progression to moderate/severe AR were determined in patients with 2 or more echocardiographic examinations. Risk factors for dilatation were tested by Cox regression to identify predictors of AR progression. ResultsAt baseline, moderate AR was present in 9 patients (5.9%) and severe AR in 4 (2.6%), of whom 3 had required aortic valve surgery. Initially, the median neoaortic root dimension was 20.05±2.4mm/m2, which increased significantly to 20.73±2.8mm/m2 (P <.001) at the end of follow-up. The mean change over time was 0.14mm/m2/y (95%CI, 0.07-0.2). Progressive AR was observed in 20 patients (13.5%) and 6 patients (4%) required aortic valve surgery. Progressive AR was associated with bicuspid valve, AR at baseline, NRD at baseline, and neoaortic root enlargement. Independent predictors were bicuspid valve (HR, 3.3; 95%CI, 1.1-15.2; P=.037), AR at baseline (HR, 5.9; 95%CI, 1.6-59.2; P=.006) and increase in NRD (HR, 4.1 95%CI, 2-13.5; P=.023). ConclusionsIn adult life, NRD and AR progress over time after ASO. Predictors of progressive AR are bicuspid valve, AR at baseline, and increase in NRD.

Accurate single image super-resolution using multi-path wide-activated residual network

In many recent image super-resolution (SR) methods based on convolutional neural networks (CNNs), the superior performance was achieved by training very large networks, which may not be suitable for real-world applications with limited computing resources. Therefore, it is necessary to develop more compact networks that achieve a better trade-off between the model size and the performance. In this paper, we propose an efficient and effective network called multi-path wide-activated residual network (MWRN). Firstly, as the basic building block of MWRN, the multi-path wide-activated residual block (MWRB) is presented to extract the multi-scale features. MWRB consists of three parallel wide-activated residual paths, where the dilated convolutions with different dilation factors are used to increase the receptive fields. Secondly, the fusional channel attention (FCA) module, which contains a bottleneck layer and a multi-path wide-activated residual channel attention (MWRCA) block, is designed to well exploit the multi-level features in MWRN. In each FCA, the MWRCA block refines the fused features by taking the interdependencies among feature channels into consideration. The experiments demonstrate that, compared with the state-of-the-art methods, the proposed MWRN model is able to provide very competitive performance with a relatively small number of parameters.

Long-Term Risk Factors for Dilatation of the Proximal Aorta in a Large Cohort of Children With Bicuspid Aortic Valve.

Patients with bicuspid aortic valve (BAV) have a higher risk of developing aortic valve dysfunction and progressive proximal aorta dilatation, which can lead to aortic dissection. To this day, identification of children at risk of developing severe aortic dilatation during their pediatric follow-up is still challenging because most studies were restricted to adult subjects. The overarching goal of this study was to identify risk factors of aortic dilatation in children with BAV. We extracted clinical and echocardiographic data of all BAV subjects aged 0 to 20 years followed at Centre Hospitalier Universitaire Sainte-Justine between 1999 and 2016. We excluded subjects with concomitant heart defects and conditions affecting proximal aorta dimensions. Proximal aorta diameters (expressed as Z scores) were modeled in relation to age and potential predictive variables in a linear mixed model. The primary outcome was the rate of dilatation. We included 761 subjects (3134 echocardiograms) in final analyses. The mean ascending aorta Z score progression rate for BAV patient with a normally functioning aortic valve was estimated at 0.05 Z score unit per year. The strongest predictors of an increased dilatation rate were severe aortic stenosis, moderate and severe aortic regurgitation, and uncorrected coarctation of the aorta. Aortic valve leaflet fusion pattern and sex were not associated with progression rate. Children with a normally functioning BAV exhibited a very slow proximal aorta dilatation rate. Ascending aorta dilatation rate was significantly increased in patients with more than mild aortic valve dysfunction but was independent from BAV leaflet fusion type.

On the computational complexity of algebraic numbers: the Hartmanis–Stearns problem revisited

— We consider the complexity of integer base expansions of algebraic irrational numbers from a computational point of view. We show that the Hartmanis–Stearns problem can be solved in a satisfactory way for the class of multistack machines. In this direction, our main result is that the base-b expansion of an algebraic irrational real number cannot be generated by a deterministic pushdown automaton. We also confirm an old claim of Cobham proving that such numbers cannot be generated by a tag machine with dilation factor larger than one.

A尺度二元最小能量多小波框架的构造

a尺度二元最小能量多小波框架的构造

Colorectal Disease Classification Using Efficiently Scaled Dilation in Convolutional Neural Network

Computer-aided diagnosis systems developed by computer vision researchers have helped doctors to recognize several endoscopic colorectal diseases more rapidly, which allows appropriate treatment and increases the patient's survival ratio. Herein, we present a robust architecture for endoscopic image classification using an efficient dilation in Convolutional Neural Network (CNNs). It has a high receptive field of view at the deep layers in increasing and decreasing dilation factor to preserve spatial details. We argue that dimensionality reduction in CNN can cause the loss of spatial information, resulting in miss of polyps and confusion in similar-looking images. Additionally, we use a regularization technique called DropBlock to reduce overfitting and deal with noise and artifacts. We compare and evaluate our method using various metrics: accuracy, recall, precision, and F1-score. Our experiments demonstrate that the proposed method provides the F1-score of 0.93 for Colorectal dataset and F1-score of 0.88 for KVASIR dataset. Experiments show higher accuracy of the proposed method over traditional methods when classifying endoscopic colon diseases.

The dilatation factor of left atrium in remote period after the mitral valve prosthesis

Objective. Studying of the morphometry indices and contractility of the heart left compartments in the left atrium reduction after prosthesis of a mitral valve.&#x0D; Materials and methods. Into the investigation 634 consequently operated patients with isolated mitral failure were included, who were surgically treated in Amosov National Institute of Cardiovascular Surgery from the 1st of January to the 1st of January 2007 yr. In all the patients the mitral valve prosthesis was performed. In the left atrium dilatation in 49 (7.7%) patients additionally its reduction was done, using paraanular plication of posterior wall of left atrium with the aim to achieve its size lesser than 5,0 cm.&#x0D; Results. Of 49 patients, suffering constant form of atrial fibrillation, thromboembolic complications have occurred in 3 (6.1%) while performance of paraanular plasty of left atrium with simultaneous elimination of its auricle. All thromboembolic complications were nonsevere, and a left atrium size did not exceeded 5.5 sm.&#x0D; Conclusion. The left atrium reduction and elimination of its auricle in the left-sided atriomegaly constitutes a significant element of the result improvement in the mitral valve prosthesis in late period of follow-up.

Causal FIR symmetric paraunitary matrix extension and construction of symmetric tight M-dilated framelets

We consider a causal FIR symmetric paraunitary (PU) matrix extension with parameters, and the constructions of symmetric orthogonal wavelets and symmetric tight framelets with an integer dilation factor M ⩾ 2 . Firstly, we propose an algorithm for factorizing a causal FIR symmetric Laurent polynomial vector into the product of order-one paraunitary matrices and constant vector. Secondly, based on the factorization algorithm, we propose a method for a causal symmetric PU extension with parameters of a Laurent polynomial vector. This method enables us to parameterize polyphase matrix whose first row is equal to the Laurent polynomial vector composed of polyphase components of given lowpass filter. And this symmetric PU extension provides a minimal factorization structure. Thirdly, we consider the constructions of symmetric orthogonal wavelets and symmetric tight framelets with integer dilation factor by the causal symmetric PU extension. Finally, several examples are provided to illustrate the construction methods proposed in this paper.

P2786Current ESC guidelines for normal ascending aortic diameter: prevalence of aortic dilatation increases to 20% in a consecutive coronary CTA population

Abstract Introduction Epidemiological studies on the prevalence of ascending aortic (AA) dilatation are scanty. Purpose To clarify prevalence of AA dilatation according to ESC 2014 guidelines and to study its risk factors. Methods This retrospective study included 1000 consecutive patients scheduled for diagnostic coronary artery computer tomography angiography (CCTA) with low to moderate pretest probability for coronary artery disease (CAD). AA diameter was measured at 3 planes; sinus valsalva, sinotubular junction and tubular part. Threshold for AA dilatation was set to &gt;40 mm (ESC 2014). Traditional risk factors for AA dilatation were collected from medical records. Aortic size index (ASI) was used as a comparative measurement. ASI is defined as the ratio between aortic diameter and body surface area (BSA). The threshold for AA dilatation was set to upper limit of normal distribution exceeding two standard deviations (95%). Heart-aorta angle (HAA, Figure) was measured as one suggestive risk factor. Results Patients' mean age was 52.9±9.8 years, 66.5% were women. The prevalence of AA dilatation in the whole study population was 20.4% according to ESC 2014 guidelines. When patients with hypertension (n=445) or coronary calcifications or stenosis in CCTA (n=375) were excluded, the prevalence of AA dilatation was 14.5% in the population of normotensive patients without CAD (n=380). According to the normal-distributed ASI values the threshold for normal dimension of sinus valsalva was defined as 23.5 mm/m2 and for tubular part 22.7 mm/m2 for normotensive patients without CAD. Using these thresholds, the prevalence of AA dilatation was 7.8% in the whole population and 7.1% in normotensive patients without CAD. Smaller HAA was associated to AA dilatation. Median HAA was 125.6° (range: 119.2–131.5°) in patients with dilated AA and 130.1° (123.7–136.4°) in patients with non-dilated AA (p&lt;0.001). Higher BSA was associated to larger AA dimensions. Risk factors for AA dilatation (according to ESC criteria) were male gender, BAV, hypertension and smoking (p&lt;0.01). Figure 1 Conclusions The prevalence of AA dilatation proved to be relatively high in this consecutive CCTA population when using ESC 2014 guidelines. Body size is associated to AA dimensions; thus, it seems reasonable to include BSA in the definition of AA dilatation. Acknowledgement/Funding Oiva Vaittinen will grant, Aarne Koskelo Foundation

Relativistic Astronomy. III. Test of Special Relativity via Doppler Effect

Abstract The “Breakthrough Starshot” program is planning to send transrelativistic probes to travel to nearby stellar systems within decades. Because the probe velocity is designed to be a good fraction of the light speed, Zhang &amp; Li recently proposed that these transrelativistic probes can be used to study astronomical objects and to test special relativity. In this work, we propose some methods to test special relativity and constrain photon mass using the Doppler effect with the images and spectral features of astronomical objects as observed in the transrelativistic probes. We introduce more general theories to set up the framework of testing special relativity, including the parametric general Doppler effect and the Doppler effect with massive photons. We find that by comparing the spectra of a certain astronomical object, one can test Lorentz invariance and constrain photon mass. Additionally, using the imaging and spectrograph capabilities of transrelativistic probes, one can test time dilation and constrain photon mass. For a transrelativistic probe with velocity v ∼ 0.2c, aperture D ∼ 3.5 cm, and spectral resolution R ∼ 100 (or 1000), we find that the probe velocity uncertainty can be constrained to σ v ∼ 0.01c (or 0.001c), and the time dilation factor uncertainty can be constrained to (or 0.001), where is the time dilation factor and γ is the Lorentz factor. Meanwhile, the photon mass limit is set to m γ ≲ 10−33 g, which is slightly lower than the energy of the optical photon.

High prevalence of ascending aortic dilatation in a consecutive coronary CT angiography patient population

ObjectivesTo clarify the prevalence and risk factors of ascending aortic (AA) dilatation according to ESC 2014 guidelines.MethodsThis study included 1000 consecutive patients scheduled for diagnostic coronary artery computed tomographic angiography. AA diameter was retrospectively measured in 3 planes: sinus valsalva, sinotubular junction, and tubular part. The threshold for AA dilatation was set to > 40 mm which has been suggested as an upper normal limit for AA diameter in ESC 2014 guidelines on aortic diseases. Aortic size index (ASI) using the ratio between aortic diameter and body surface area (BSA) was applied as a comparative measurement. The threshold for AA dilatation was set to the upper limit of normal distribution exceeding two standard deviations (95%). Risk factors for AA dilatation were collected from medical records.ResultsThe patients’ mean age was 52.9 ± 9.8 years (66.5% women). The prevalence of AA dilatation was 23.0% in the overall study population (52.5% males) and 15.1% in the subgroup of patients with no coronary artery disease or bicuspid (BAV)/mechanical aortic valve (n = 365). According to the normal-distributed ASI values, the threshold for sinus valsalva was defined as 23.2 mm/m2 and for tubular part 22.2 mm/m2 in the subgroup. Higher BSA was associated with larger AA dimensions (r = 0.407, p < 0.001). Male gender (p < 0.001), BAV (p < 0.001), hypertension (p = 0.009) in males, and smoking (p < 0.001) appeared as risk factors for AA dilatation.ConclusionsThe prevalence of AA dilatation is high with current ESC guidelines for normal AA dimension, especially in males. Body size is strongly associated with AA dimensions; it would be more reliable to use BSA-adjusted AA diameters for the definition of AA dilatation.Key Points• The prevalence of AA dilatation is high in patients who are candidates for coronary CT angiography.• Body size is strongly associated with AA dimensions.

M-band flexible wavelet transform and its application to the fault diagnosis of planetary gear transmission systems

Abstract The fault diagnosis of planetary gear transmission systems is crucial for the safety of machineries and equipment. To identify the underlying fault features in measured signals, a novel M-band flexible wavelet transform is constructed. This transform provides a denser sampling of the time–frequency plane and preserves tunable filter parameters and dilation factors. A perfect reconstruction condition of the proposed transform is established, and its corresponding wavelet filter bank is designed to satisfy the perfect reconstruction condition. A numerical implementation algorithm of M-band flexible wavelet transform is investigated using a multirate filter bank and fast Fourier transform. Denoising the simulation signals demonstrates that the proposed transform exhibits better performance than analytic flexible wavelet transform, orthogonal wavelet transform, and biorthogonal wavelet transform. A new fault diagnosis method for planetary gear transmission systems is proposed on the basis of M-band flexible wavelet transform and spectral negentropy. Experimental and comparative results show that the proposed method can be more effectively and accurately applied to the fault diagnosis of planetary gear transmission systems compared with typical fault diagnosis methods based on analytic flexible wavelet transform, Morlet wavelet transform, and infograms.

Comparative study of shear strength characteristics of dry cohesionless sands from triaxial, plane-strain and direct shear tests

ABSTRACT Knowledge of strength properties and deformational behaviour of soils under different loading conditions is necessary in the analysis of most of the geotechnical engineering problems. This paper presents a comparative study of shear strength characteristics of sands as obtained from triaxial, plane-strain and direct shear test results. The experimental results on shear strength characteristics of dry sands obtained from triaxial, plane-strain and direct shear tests, were analyzed in order to investigate the effect of soil relative density or soil porosity on the angle of shearing resistance, dilatancy factor, particles interlocking, and volumetric strain and axial strain at failure. Furthermore, the results were used to develop correlations connecting between the angle of shearing resistance of triaxial condition test and the direct shear test, and between the angle of shearing resistance of plane-strain and triaxial compression conditions. The correlations developed take into account the interaction between soil relative density, dilatancy factor and particles interlocking. Good agreement has been obtained between the predicted results values using the proposed methods and the results of the present experimental investigation and those available in the literature

Diagnosis of Delusion and Hallucination from Schizophrenia Patient Using RADWT.

In this paper, early detection of schizophrenia types such as hallucination and delusion propose through the high Q-factor of RADWT in EEG signal acquired during the cognitive task of the patient. The earlier diagnose obtains from the energy distribution of the EEG signal in the high resolution via optimum tuning in dilation factor,which influences the Q-factor, redundancy and ringing in the EEG signal. The early detection of type of schizophrenia prevents the illness progression and lifelong disease. In existing clinical trial, the psych clinician diagnose only the schizophrenia disease through the standard DSM screening question and Prodromal signs checklist according to the standard of American Psychiatric Association. Furthermore, clinician tries to diagnose the disease through brain imaging and EEG signal. However, procedure in the diagnosis of Schizophrenia possible only in the acute stage, minimum after 2years of illness progression and still sub classification of the type of schizophrenia is a challenging task. In the proposed system, we acquire EEG signal during the three conditions such as reverse counting of the number, screening questions (DSM), and eye rest state with a distance of 1-m part of the clinician and patient to analyse cognitive behaviour. From the result of 25 patients EEG, signal during cognitive task show the different sub band energy pattern in RADWT to distinguish hallucination and delusion patient exactly for 21 patients and provide 84% of accuracy in sub-classification of type schizophrenia.

Single image rain removal via densely connected contextual and semantic correlation net

Rainy images severely degrade visibility. Thus, deraining is an important task for applications ranging from image processing to computer vision. We propose a deep learning-based method to remove rain streaks from a single image. Specifically, we first design a deraining unit that employs dilation convolution and squeeze-and-excitation operations, respectively, to obtain more spatial contextual information and semantic correlation. In the deraining unit, multifeatures at different levels can be obtained by using convolutions with different dilation factors, and they are fused to maintain the primary features of rain streaks. Then, we interconnect the deraining units by dense connections that can maximize the information flow along features from different levels and make them be associated. Both deraining units and dense connections make our network have stronger representative ability of the rain streaks layer. Experimental results show that our proposed deraining method outperforms state-of-the-art methods by a good margin in Rain100H, Rain100L, and Rain1200 datasets, while using fewer parameters.

Convergence of subdivision schemes on Riemannian manifolds with nonpositive sectional curvature

This paper studies well-definedness and convergence of subdivision schemes which operate on Riemannian manifolds with nonpositive sectional curvature. These schemes are constructed from linear ones by replacing affine averages by the Riemannian centre of mass. In contrast to previous work, we consider schemes without any sign restriction on the mask, and our results apply to all input data. We also analyse the Hölder continuity of the resulting limit curves. Our main result states that if the norm of the derived scheme (resp. iterated derived scheme) is smaller than the corresponding dilation factor then the adapted scheme converges. In this way, we establish that convergence of a linear subdivision scheme is almost equivalent to convergence of its nonlinear manifold counterpart.

Differences in Echocardiographic Measures of Aortic Dimensions by Race

It is not clear whether there are differences in aortic dimensions by race. Our hypothesis was that race-specific differences in aortic size exist. We compared the relation between race and aortic dimensions among 15,295 adults without known risk factors for cardiovascular disease or aortic dilatation, who underwent clinically indicated transthoracic echocardiography. We compared inner edge-to-inner edge measurements between whites (n = 12,932), blacks (n = 958), Asians (n = 827), Hispanics (n = 366), Native Americans (n = 38), and others (n = 174). Multivariate analysis compared measurements indexed with body surface area (BSA) between races and adjusted for variables including age, gender, and mean blood pressure. Mean age was 49.9 ± 17.6 years, and 58.7% were female. On gender-specific comparisons, there were significant differences in aortic size between races (p <0.001 for each). Using whites as a baseline, multivariable analysis demonstrated that blacks had smaller BSA-indexed aortic sinus (-0.34 mm/m2, p <0.001) and ascending aorta (-0.43 mm/m2, p <0.001) dimensions; Asians had larger BSA-indexed aortic sinus (0.36 mm/m2, p <0.001), ascending aorta (0.41 mm/m2, p <0.001), and aortic arch (0.20 mm/m2, p = 0.002) dimensions; Hispanics had larger BSA-indexed aortic arch dimensions (0.15 mm/m2, p = 0.01); Native Americans had increased BSA-indexed aortic arch dimensions (0.32 mm/m2, p = 0.01); and other races had increased BSA-indexed aortic arch dimensions (0.11 mm/m2, p = 0.03). In a cohort without known risk factors for aortic dilatation, race is associated with significant differences in aortic dimensions. In conclusion, these findings suggest that reference ranges for aortic size should be established using racially diverse cohorts to prevent misdiagnosis of aortic dilatation based on race.