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关键词： Vehicle detection   3D vehicle reconstruction   Pose estimation   Multi-branch CNN   Active shape model  

摘要： The 3D reconstruction of objects is a prerequisite for many highly relevant applications of computer vision such as mobile robotics or autonomous driving. To deal with the inverse problem of reconstructing 3D objects from their 2D projections, a common strategy is to incorporate prior object knowledge into the reconstruction approach by establishing a 3D model and aligning it to the 2D image plane. However, current approaches are limited due to inadequate shape priors and the insufficiency of the derived image observations for a reliable alignment with the 3D model. The goal of this paper is to show how 3D object reconstruction can profit from a more sophisticated shape prior and from a combined incorporation of different observation types inferred from the images. We introduce a subcategory-aware deformable vehicle model that makes use of a prediction of the vehicle type for a more appropriate regularisation of the vehicle shape. A multi-branch CNN is presented to derive predictions of the vehicle type and orientation. This information is also introduced as prior information for model fitting. Furthermore, the CNN extracts vehicle keypoints and wireframes, which are well-suited for model-to-image association and model fitting. The task of pose estimation and reconstruction is addressed by a versatile probabilistic model. Extensive experiments are conducted using two challenging real-world data sets on both of which the benefit of the developed shape prior can be shown. A comparison to state-of-the-art methods for vehicle pose estimation shows that the proposed approach performs on par or better, confirming the suitability of the developed shape prior and probabilistic model for vehicle reconstruction.

关键词： Biplots   CVA   Categorical data analysis  

摘要： Techniques to visualise and understand large amounts of data are of paramount importance. In most settings, this data is usually multivariate, which further stresses the need for effective visualisation techniques. Multivariate visualisation techniques such as canonical variate analysis (CVA) biplots allow for simultaneous lower-dimensional visualisation and data classification by incorporating class-specific data. CVA biplots, however, are currently restricted to numerical data. Through combining concepts from both CVA and non-linear principal component analysis (PCA) biplots, a new biplot construction methodology that improves on the traditional CVA biplot by allowing for categorical variables is proposed. This technique, named CVA(H-r), is showcased using the established mushroom data set, which contains a mix of categorical and ordinal variables. This novel method improves upon existing biplot construction in terms of classification accuracy and class separation. (C) 2021 Elsevier B.V. All rights reserved.

关键词： business models   categorization strategies   category priming   digital   market entry   non-market stakeholders  

摘要： The rise of the 'digital age' presents unique challenges for firms entering new markets and deciding 'where' to compete - a pivotal topic in corporate strategy. Particularly, it is not clear what the opportunities and implications are for digital new entrants as they position their disruptive business offerings in the category system, in particular vis-a-vis non-market stakeholders. In this article, we qualitatively investigate how two icons of the 'sharing economy', Uber and BlaBlaCar, pursued two distinct categorization strategies which were incumbent-focused and economic versus emergent-focused and non-economic. Our longitudinal comparative case study reveals how digital new entrants, through self-categorization, can enduringly impact the nature of the responses of non-market stakeholders. The mechanism at play is 'category priming' - the process of directing stakeholders' selective attention towards, or away from, the commonalities shared with a specific market category - and its stickiness over time. In particular, the distinct categorization strategies primed stakeholders to focus (Uber) or not focus (BlaBlaCar) on similarities between the entrant and an established category, which triggered polarized responses from media and regulators and resulted in a 'sticky' association regardless of repositioning efforts. Our contribution dissects the constituents and consequences of these strategies and discusses implications for future research on digital market entry, strategic categorization, and business models.

关键词： IoT   Sensors   Coal gangue "category" recognition   Recognition accuracy   Impact-slip  

摘要： Advancing of the intelligent fully mechanized caving mining technology (IFMCMT) is the fundamental method to improve the output of coal resources. Accurate identification of coal gangue is the necessary condition for the re-alization of IFMCMT. To achieve coal gangue recognition, Internet of Things (IoT) technology and impact-slip con-tact characteristics based method for coal gangue "category" recognition is proposed in this paper. An IoT recognition system is constructed, then impact-slip test bed between coal gangue mixture and the hydraulic sup-port is designed. Secondly, coal gangue "category" recognition parameters are discussed, hereby multi-dimensional contact characteristic information acquisition system is constructed. After that, impact-slip tests were carried out to extract and process the multi-source and multi-azimuth signals, and three kinds of data sam-ples were obtained. Finally, 10 kinds of classification algorithms were selected for random classification recogni-tion of coal gangue "caving category" and "shut down category". Coal gangue "category" recognition ability by algorithms, signal types and data types is compared, which provides the theoretical basis for further classification recognition effect improving research. Research show that coal gangue "category" random recognition accuracy can reach to 0.935 (Define the range of recognition accuracy as 1), which proves the effectiveness of "category" by IoT system and impact-slip contact characteristics. (c) 2021 Elsevier B.V. All rights reserved.

关键词： Affine supergroup scheme   Tensor category   Module category   Twist   Triangular Hopf algebra  

摘要： Let k be an algebraically closed field of characteristic 0 or p > 2. Let g be an affine supergroup scheme over k. We classify the indecomposable exact module categories over the tensor category sCoh f (g) of (coherent sheaves of) finite dimensional O(g)-supermodules in terms of (H, Psi) equivariant coherent sheaves on g. We deduce from it the classification of indecomposable geometrical module categories over sRep(c). When g is finite, this yields the classification of all indecomposable exact module categories over the finite tensor category sRep(c). In particular, we obtain a classification of twists for the supergroup algebra kg of a finite supergroup scheme c, and then combine it with [7, Corollary 4.1] to classify finite dimensional triangular Hopf algebras with the Chevalley property over k. (C) 2021 Elsevier B.V. All rights reserved.

关键词： Etonogestrel implant   Weight   Adolescents  

摘要： Purpose: The purpose of this study was to determine if initiation and use of the etonogestrel implant was associated with differential weight gain in patients who were overweight or obese compared with normal-weight patients. Methods: This is a cohort study of 1,024 patients between ages of 13 and 25 years seen in a Title X clinic who received the etonogestrel implant from 2007 to 2019 and had weight measurements at implant insertion and 6-18 months before (preinsertion) and after insertion (postinsertion). Results: Patients, regardless of weight category (normal weight, overweight, and obese), increased weight in kilograms (kg) from preinsertion to insertion (1.16 f 4.16 kg, 2.79 f 5.35 kg, and 4.54 f 7.71 kg, respectively) and from insertion to postinsertion (1.38 f 4.37 kg, 2.94 f 6.97 kg, and 3.66 f 6.53, respectively). However, there was no increase in the amount gained comparing pre insertion to insertion with insertion to postinsertion. Patients who removed the implant (n = 84) for weight concerns did have increased weight change and a greater percent who gained >5% postinsertion as compared with those who removed the implant for other reasons or did not have the implant removed (65.5% vs. 34.2% vs. 39.2%, respectively, p = .03). Conclusions: Overweight and obese adolescents are at risk of weight gain over time, but placement of the implant did not accelerate the rate of gain from preinsertion to postinsertion. However, patients who removed the implant specifically because of weight gain did gain more weight after insertion compared with before. Clinicians should help patients evaluate the benefits and risks of highly effective contraceptive options as well as be aware of a subset of patients who do gain weight with use of the implant. (c) 2021 Society for Adolescent Health and Medicine. All rights reserved.

关键词： diffusion magnetic resonance imaging   hippocampus   humans   learning   memory   white matter  

摘要： Prior work suggests that complementary white matter pathways within the hippocampus (HPC) differentially support the learning of specific versus general information. In particular, while the trisynaptic pathway (TSP) rapidly forms memories for specific experiences, the monosynaptic pathway (MSP) slowly learns generalities. However, despite the theorized significance of such circuitry, characterizing how information flows within the HPC to support learning in humans remains a challenge. We leveraged diffusion-weighted imaging as a proxy for individual differences in white matter structure linking key regions along with TSP (HPC subfields CA(3) and CA(1)) and MSP (entorhinal cortex and CA(1)) and related these differences in hippocampal structure to category learning ability. We hypothesized that learning to categorize the "exception" items that deviated from category rules would benefit from TSP-supported mnemonic specificity. Participant-level estimates of TSP- and MSP-related integrity were constructed from HPC subfield connectomes of white matter streamline density. Consistent with theories of TSP-supported learning mechanisms, we found a specific association between the integrity of CA(3)-CA(1) white matter connections and exception learning. These results highlight the significant role of HPC circuitry in complex human learning.

关键词： Thyroid nodule   Pediatric   FNAB   Cytological category   Outcome  

摘要： Purpose The rate of malignancy (ROM) among pediatric studies using the Bethesda System is 39.5% and 41.5% for atypia of undetermined significance/follicular lesion of undetermined significance and for suspected follicular neoplasm, respectively. Data reported on the basis of Bethesda System showed lower ROM in adults with indeterminate nodules (30.5 and 28.9% respectively). Studies on adults based on the Italian Society of Anatomic Pathology and Cytology (SIAPEC) classification, report ROM of 14.2% for TIR3a and 44.6% for TIR3b category, showing greater sensitivity in detecting malignancy. To date, no performance data are available about SIAPEC classification in pediatric age. Methods Retrospective data were collected from 200 pediatric subjects with thyroid nodules in the period 2000-2020. Results The distribution of cytological categories after fine needle aspiration biopsy (FNAB) was 7 TIR1, 4 TIR1c, 22 TIR2, 14 TIR3a, 9 TIR3b, 3 TIR4, and 16 TIR5. The surgical approach was performed in 40/200 subjects, with total ROM of 65% (0% for TIR1-TIR3a, 77.8% for TIR3b, and 100% for TIR4-TIR5). Total FNAB accuracy was 95%, while the sensibility and specificity were 92.3 and 92.6%, respectively. Conclusions The reported data seem to confirm a greater sensitivity of SIAPEC classification to identify malignancy within the indeterminate category also in pediatric age and not only in adulthood. This finding may orient clinicians toward clinical follow-up for the indeterminate TIR3a group and toward surgical approach with total thyroidectomy in the indeterminate TIR3b group, although this indication should be confirmed in further national multicenter studies including larger cohorts.

关键词： bilingual   noun   picture naming   translation   verb  

摘要： Bilingual speakers are less accurate and slower than monolinguals in word production. This bilingual cost has been demonstrated primarily for nouns. This study compared verb and noun retrieval to better understand bilingual lexical representation and test alternate hypotheses about bilingual cost. Picture naming speeds from highly proficient English-Spanish bilinguals showed a smaller bilingual cost for verbs compared to nouns. In Experiment 1, picture naming speeds were influenced by name agreement, age-of-acquisition and word length. Additionally, noun (but not verb) naming speed was predicted by word frequency. Experiment 2 examined two potential explanations for the smaller bilingual cost for verbs: verbs experience weaker cross-language interference (measured by translation speed) and smaller frequency effects. Both these predictions were confirmed, showing crucial differences between verbs and nouns and suggesting that cross-language facilitation rather than interference influences bilingual lexical retrieval, and that the frequency lag account of bilingual cost is more applicable to nouns than to verbs. We propose a Bilingual Integrated Grammatical Category model for highly proficient bilinguals to represent lexical category differences.

关键词： 14F06   14F08   14F20  

摘要： We show that the triangulated category of bounded constructible complexes on an algebraic varietyXover an algebraically closed field is equivalent to the bounded derived category of the abelian category of constructible sheaves onX, extending a theorem of Nori to the case of positive characteristic.