335 research outputs found

    COCO_TS Dataset: Pixel-level Annotations Based on Weak Supervision for Scene Text Segmentation

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    The absence of large scale datasets with pixel-level supervisions is a significant obstacle for the training of deep convolutional networks for scene text segmentation. For this reason, synthetic data generation is normally employed to enlarge the training dataset. Nonetheless, synthetic data cannot reproduce the complexity and variability of natural images. In this paper, a weakly supervised learning approach is used to reduce the shift between training on real and synthetic data. Pixel-level supervisions for a text detection dataset (i.e. where only bounding-box annotations are available) are generated. In particular, the COCO-Text-Segmentation (COCO_TS) dataset, which provides pixel-level supervisions for the COCO-Text dataset, is created and released. The generated annotations are used to train a deep convolutional neural network for semantic segmentation. Experiments show that the proposed dataset can be used instead of synthetic data, allowing us to use only a fraction of the training samples and significantly improving the performances

    Rationale and design of the dual-energy computed tomography for ischemia determination compared to “gold standard” non-invasive and invasive techniques (DECIDE-Gold) : a multicenter international efficacy diagnostic study of rest-stress dual-energy computed tomography angiography with perfusion

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    Background: Dual-energy CT (DECT) has potential to improve myocardial perfusion for physiologic assessment of coronary artery disease (CAD). Diagnostic performance of rest-stress DECT perfusion (DECTP) is unknown. Objective: DECIDE-Gold is a prospective multicenter study to evaluate the accuracy of DECT to detect hemodynamic (HD) significant CAD, as compared to fractional flow reserve (FFR) as a reference standard. Methods: Eligible participants are subjects with symptoms of CAD referred for invasive coronary angiography (ICA). Participants will undergo DECTP, which will be performed by pharmacological stress, and participants will subsequently proceed to ICA and FFR. HD-significant CAD will be defined as FFR\ua0 64\ua00.80. In those undergoing myocardial stress imaging (MPI) by positron emission tomography (PET), single photon emission computed tomography (SPECT) or cardiac magnetic resonance (CMR) imaging, ischemia will be graded by % ischemic myocardium. Blinded core laboratory interpretation will be performed for CCTA, DECTP, MPI, ICA, and FFR. Results: Primary endpoint is accuracy of DECTP to detect 651 HD-significant stenosis at the subject level when compared to FFR. Secondary and tertiary endpoints are accuracies of combinations of DECTP at the subject and vessel levels compared to FFR and MPI. Conclusion: DECIDE-Gold will determine the performance of DECTP for diagnosing ischemia

    Peluang Peningkatan Tipe Terminal di Kecamatan Banyumaik (Analisis Demand dan Supply)

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    Kecamatan Banyumanik merupakan kecamatan yang terus mengalami perkembangan baik dari jumlah penduduk maupun pelayanan kotanya. Kecamatan ini juga berbatasan langsung dengan kabupaten Semarang dan menjadi gerbang koridor semarang atas atau semarang bagian Selatan sehingga memiliki pergerakan yang tinggi sebagai jalur keluar masuknya kota Semarang. Pergerakan yang tinggi tersebut tidak diimbangi dengan ketersediaan fasilitas transportasi pendukung yaitu terminal. Terminal merupakan salah satu fasilitas utama yang memiliki peran penting dalam sistem transportasi. Menurut keputusan menteri nomor 35 tahun 2003 pengertian terminal adalah prasarana transportasi jalan untuk keperluan memuat dan menurunkan orang dan/atau barang serta mengatur kedatangan dan pemberangkatan kendaraan umum, yang merupakan salah satu wujud simpul jaringan transportasi. Terminal juga memiliki peran yang penting sebagai unsur tata ruang dalam kaitannya untuk meningkatkan mobilitas dan efisiensi kehidupan kota. Terminal merupakan tempat untuk mengurangi kemacetan dimana dapat mengatur lokasi pergantian moda transportasi menjadi lebih teratur. Lokasi sebuah terminal harus sesuai dengan rencana tata ruang wilayah (RTRW) dan sesuai dengan kebutuhan masyarakat Di kecamatan Banyumanik hanya memiliki sub terminal atau terminal bantu yang berfungsi sebagai tempat transit dan pergantian moda. Demand yang tinggi terhadap fasilitas transportasi tersebut tidak sebanding dengan supply fasilitas terminal yang tersedia sehingga mengakibatkan timbulnya titik-titik baru yang digunakan masyarakat untuk menunggu angkutan yaitu terminal bayangan. Terminal bayangan ini muncul karena adanya demand yang tinggi dari mayarakat banyumanik terhadap kebutuhan sarana transportasi dan efisiensi waktu. Ketidakseimbangan antara demand dan supply ini mengakibatkan berbagai dampak makro maupun mikro terhadap lalu lintas maupun jaringan angkutan di Kecamatan Banyumanik dan kota Semarang

    Preferential Paths of Air-water Two-phase Flow in Porous Structures with Special Consideration of Channel Thickness Effects.

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    Accurate understanding and predicting the flow paths of immiscible two-phase flow in rocky porous structures are of critical importance for the evaluation of oil or gas recovery and prediction of rock slides caused by gas-liquid flow. A 2D phase field model was established for compressible air-water two-phase flow in heterogenous porous structures. The dynamic characteristics of air-water two-phase interface and preferential paths in porous structures were simulated. The factors affecting the path selection of two-phase flow in porous structures were analyzed. Transparent physical models of complex porous structures were prepared using 3D printing technology. Tracer dye was used to visually observe the flow characteristics and path selection in air-water two-phase displacement experiments. The experimental observations agree with the numerical results used to validate the accuracy of phase field model. The effects of channel thickness on the air-water two-phase flow behavior and paths in porous structures were also analyzed. The results indicate that thick channels can induce secondary air flow paths due to the increase in flow resistance; consequently, the flow distribution is different from that in narrow channels. This study provides a new reference for quantitatively analyzing multi-phase flow and predicting the preferential paths of immiscible fluids in porous structures

    The compositional and evolutionary logic of metabolism

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    Metabolism displays striking and robust regularities in the forms of modularity and hierarchy, whose composition may be compactly described. This renders metabolic architecture comprehensible as a system, and suggests the order in which layers of that system emerged. Metabolism also serves as the foundation in other hierarchies, at least up to cellular integration including bioenergetics and molecular replication, and trophic ecology. The recapitulation of patterns first seen in metabolism, in these higher levels, suggests metabolism as a source of causation or constraint on many forms of organization in the biosphere. We identify as modules widely reused subsets of chemicals, reactions, or functions, each with a conserved internal structure. At the small molecule substrate level, module boundaries are generally associated with the most complex reaction mechanisms and the most conserved enzymes. Cofactors form a structurally and functionally distinctive control layer over the small-molecule substrate. Complex cofactors are often used at module boundaries of the substrate level, while simpler ones participate in widely used reactions. Cofactor functions thus act as "keys" that incorporate classes of organic reactions within biochemistry. The same modules that organize the compositional diversity of metabolism are argued to have governed long-term evolution. Early evolution of core metabolism, especially carbon-fixation, appears to have required few innovations among a small number of conserved modules, to produce adaptations to simple biogeochemical changes of environment. We demonstrate these features of metabolism at several levels of hierarchy, beginning with the small-molecule substrate and network architecture, continuing with cofactors and key conserved reactions, and culminating in the aggregation of multiple diverse physical and biochemical processes in cells.Comment: 56 pages, 28 figure

    Diagnosis of obstructive coronary artery disease using computed tomography angiography in patients with stable chest pain depending on clinical probability and in clinically important subgroups: meta-analysis of individual patient data

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    OBJECTIVE: To determine whether coronary computed tomography angiography (CTA) should be performed in patients with any clinical probability of coronary artery disease (CAD), and whether the diagnostic performance differs between subgroups of patients. DESIGN: Prospectively designed meta-analysis of individual patient data from prospective diagnostic accuracy studies. DATA SOURCES: Medline, Embase, and Web of Science for published studies. Unpublished studies were identified via direct contact with participating investigators. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Prospective diagnostic accuracy studies that compared coronary CTA with coronary angiography as the reference standard, using at least a 50% diameter reduction as a cutoff value for obstructive CAD. All patients needed to have a clinical indication for coronary angiography due to suspected CAD, and both tests had to be performed in all patients. Results had to be provided using 2×2 or 3×2 cross tabulations for the comparison of CTA with coronary angiography. Primary outcomes were the positive and negative predictive values of CTA as a function of clinical pretest probability of obstructive CAD, analysed by a generalised linear mixed model; calculations were performed including and excluding non-diagnostic CTA results. The no-treat/treat threshold model was used to determine the range of appropriate pretest probabilities for CTA. The threshold model was based on obtained post-test probabilities of less than 15% in case of negative CTA and above 50% in case of positive CTA. Sex, angina pectoris type, age, and number of computed tomography detector rows were used as clinical variables to analyse the diagnostic performance in relevant subgroups. RESULTS: Individual patient data from 5332 patients from 65 prospective diagnostic accuracy studies were retrieved. For a pretest probability range of 7-67%, the treat threshold of more than 50% and the no-treat threshold of less than 15% post-test probability were obtained using CTA. At a pretest probability of 7%, the positive predictive value of CTA was 50.9% (95% confidence interval 43.3% to 57.7%) and the negative predictive value of CTA was 97.8% (96.4% to 98.7%); corresponding values at a pretest probability of 67% were 82.7% (78.3% to 86.2%) and 85.0% (80.2% to 88.9%), respectively. The overall sensitivity of CTA was 95.2% (92.6% to 96.9%) and the specificity was 79.2% (74.9% to 82.9%). CTA using more than 64 detector rows was associated with a higher empirical sensitivity than CTA using up to 64 rows (93.4% v 86.5%, P=0.002) and specificity (84.4% v 72.6%, P<0.001). The area under the receiver-operating-characteristic curve for CTA was 0.897 (0.889 to 0.906), and the diagnostic performance of CTA was slightly lower in women than in with men (area under the curve 0.874 (0.858 to 0.890) v 0.907 (0.897 to 0.916), P<0.001). The diagnostic performance of CTA was slightly lower in patients older than 75 (0.864 (0.834 to 0.894), P=0.018 v all other age groups) and was not significantly influenced by angina pectoris type (typical angina 0.895 (0.873 to 0.917), atypical angina 0.898 (0.884 to 0.913), non-anginal chest pain 0.884 (0.870 to 0.899), other chest discomfort 0.915 (0.897 to 0.934)). CONCLUSIONS: In a no-treat/treat threshold model, the diagnosis of obstructive CAD using coronary CTA in patients with stable chest pain was most accurate when the clinical pretest probability was between 7% and 67%. Performance of CTA was not influenced by the angina pectoris type and was slightly higher in men and lower in older patients. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42012002780

    Prevalence and clinical significance of collateral findings detected by chest computed tomography in patients undergoing atrial fibrillation ablation

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    Aims Chest computed tomography (CT) scanning is increasingly used as an imaging technique in patients undergoing atrial fibrillation (AF) catheter ablation. Chest CT scans visualize organs other than the heart and collateral findings may be identified incidentally. Our study aims to assess the prevalence and clinical relevance of such collateral findings in patients undergoing AF ablation. Methods and results One hundred and seventy-three patients (127 males, age 59 +/- 10 years) underwent chest CT scan for image integration in AF ablation. Collateral findings from visualized thoracic and upper abdominal organs were collected. Findings that required further investigations or treatment according to current guidelines were considered as clinically significant. A total of 164 collateral findings were identified in 97 (56%) patients, and most patients showed abnormalities of the lungs (67 patients, 39%). Forty-nine (28%) patients had clinically significant findings needing further investigation and 17 (10%) of them required specific treatments, including three cases (1.7%) of lung malignancy. Conclusions Chest CT images acquired for integration in AF ablation should be read thoroughly as they may serve as a screening tool for otherwise unrecognized clinically significant conditions of the heart, lungs, or other visualized organs
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