1,592 research outputs found

    Object-Proposal Evaluation Protocol is 'Gameable'

    Full text link
    Object proposals have quickly become the de-facto pre-processing step in a number of vision pipelines (for object detection, object discovery, and other tasks). Their performance is usually evaluated on partially annotated datasets. In this paper, we argue that the choice of using a partially annotated dataset for evaluation of object proposals is problematic -- as we demonstrate via a thought experiment, the evaluation protocol is 'gameable', in the sense that progress under this protocol does not necessarily correspond to a "better" category independent object proposal algorithm. To alleviate this problem, we: (1) Introduce a nearly-fully annotated version of PASCAL VOC dataset, which serves as a test-bed to check if object proposal techniques are overfitting to a particular list of categories. (2) Perform an exhaustive evaluation of object proposal methods on our introduced nearly-fully annotated PASCAL dataset and perform cross-dataset generalization experiments; and (3) Introduce a diagnostic experiment to detect the bias capacity in an object proposal algorithm. This tool circumvents the need to collect a densely annotated dataset, which can be expensive and cumbersome to collect. Finally, we plan to release an easy-to-use toolbox which combines various publicly available implementations of object proposal algorithms which standardizes the proposal generation and evaluation so that new methods can be added and evaluated on different datasets. We hope that the results presented in the paper will motivate the community to test the category independence of various object proposal methods by carefully choosing the evaluation protocol.Comment: 15 pages, 11 figures, 4 table

    DANTE: Deep AlterNations for Training nEural networks

    Full text link
    We present DANTE, a novel method for training neural networks using the alternating minimization principle. DANTE provides an alternate perspective to traditional gradient-based backpropagation techniques commonly used to train deep networks. It utilizes an adaptation of quasi-convexity to cast training a neural network as a bi-quasi-convex optimization problem. We show that for neural network configurations with both differentiable (e.g. sigmoid) and non-differentiable (e.g. ReLU) activation functions, we can perform the alternations effectively in this formulation. DANTE can also be extended to networks with multiple hidden layers. In experiments on standard datasets, neural networks trained using the proposed method were found to be promising and competitive to traditional backpropagation techniques, both in terms of quality of the solution, as well as training speed.Comment: 19 page

    Sectoral R&D intensity and exchange rate volatility: A panel study on economies of the OECD

    Full text link
    A recent literature has pointed at potential negative effects of exchange rate volatility on innovation. In this paper, we propose that there may be a direct effect as well as an indirect effect via export activity. We test these hypotheses for sectoral R&D intensities using OECD panel data for manufacturing and services sectors for 14 OECD economies and the years 1987 - 2003. We find that the direct negative effect of volatility is pronounced in manufacturing sector but is dominated by the indirect effect via the export channel. Services do not face any effects of volatility on R&D intensities. While it is not clear which channel dominates our results confirm that there is a negative volatility affect related to openness on a sectoral level

    A CEP215-HSET complex links centrosomes with spindle poles and drives centrosome clustering in cancer.

    Get PDF
    Numerical centrosome aberrations underlie certain developmental abnormalities and may promote cancer. A cell maintains normal centrosome numbers by coupling centrosome duplication with segregation, which is achieved through sustained association of each centrosome with a mitotic spindle pole. Although the microcephaly- and primordial dwarfism-linked centrosomal protein CEP215 has been implicated in this process, the molecular mechanism responsible remains unclear. Here, using proteomic profiling, we identify the minus end-directed microtubule motor protein HSET as a direct binding partner of CEP215. Targeted deletion of the HSET-binding domain of CEP215 in vertebrate cells causes centrosome detachment and results in HSET depletion at centrosomes, a phenotype also observed in CEP215-deficient patient-derived cells. Moreover, in cancer cells with centrosome amplification, the CEP215-HSET complex promotes the clustering of extra centrosomes into pseudo-bipolar spindles, thereby ensuring viable cell division. Therefore, stabilization of the centrosome-spindle pole interface by the CEP215-HSET complex could promote survival of cancer cells containing supernumerary centrosomes.S.C. is supported by UK Medical Research Council (MC_U105185859). This work was made possible by funding from Cancer Research UK (C14303/A17197). We acknowledge the support of the University of Cambridge and Hutchison Whampoa Ltd.This is the final version of the article. It first appeared from Nature Publishing Group via https://doi.org/10.1038/ncomms1100

    Presence of rd8 mutation does not alter the ocular phenotype of late-onset retinal degeneration mouse model.

    Get PDF
    PurposeA spontaneous frameshift mutation, c.3481delC, in the Crb1 gene is the underlying cause of dysplasia and retinal degeneration in rd8 mice. The rd8 mutation is found in C57BL/6N but not in C57BL/6J mouse sub-strains. The development of ocular pathology in single knockout Ccl2-/-, Cx3cr1-/- and in double knockout Ccl2-/-, Cx3cr1-/- mice raised on a C57BL/6 background has been reported to depend on the presence of a rd8 mutation. In this study, we investigated the influence of the rd8 mutation on the retinal pathology that we previously described in the late-onset retinal degeneration (L-ORD) mouse model with a heterozygous S163R mutation in the C1q-tumor necrosis factor-related protein-5Ctrp5+/- gene that was generated on a C57BL/6J background.MethodsMouse lines carrying the Ctrp5 S163R and rd8 mutations (Ctrp5+/-;rd8/rd8), corresponding controls without the rd8 mutation (Ctrp5+/-;wt/wt), and wild-type mice with and without the rd8 mutation (Wtrd8/rd8 and Wtwt/wt, respectively) were generated by systematic breeding of mice in our L-ORD mouse colony. Genotyping the mice for the rd8 (del C at nt3481 in Crb1) and Ctrp5 S163R mutations was performed with allelic PCR or sequencing. Retinal morphology was studied with fundus imaging, histology, light microscopy, electron microscopy, and immunohistochemistry.ResultsGenotype analysis of the mice in L-ORD mouse colony detected the rd8 mutation in the homozygous and heterozygous state. Fundus imaging of wild-type mice without the rd8 mutation (Wtwt/wt) revealed no autofluorescence (AF) spots up to 6-8 months and few AF spots at 21 months. However, the accumulation of AF lesions accelerated with age in the Ctrp5+/- mice that lack the rd8 mutation (Ctrp5+/-;wt/wt). The number of AF lesions was significantly increased (p<0.001), and they were small and uniformly distributed throughout the retina in the 21-month-old Ctrp5+/-;wt/wt mice when compared to the age-matched controls. Wild-type and Ctrp5+/- mice with the rd8 mutation (Wtrd8/rd8 and Ctrp5+/-;rd8/rd8, respectively) revealed an integrated retinal architecture with well-defined outer segments/inner segments (OS/IS), outer nuclear layer (ONL), outer plexiform layer (OPL), and inner nuclear layer (INL). The presence of pseudorosette structures reported in the rd8 mice between the ONL and the INL in the ventral quadrant of the retina was not observed in all genotypes studied. Further, the external limiting membrane was continuous in the Ctrp5+/-;rd8/rd8 and Wtrd8/rd8 mice. Evaluation of the retinal phenotype revealed that the Ctrp5+/-;wt/wt mice developed characteristic L-ORD pathology including age-dependent accumulation of AF spots, development of sub-retinal, sub-RPE, and basal laminar deposits, and Bruch's membrane abnormalities at older age, while these changes were not observed in the age-matched littermate WTwt/wt mice.ConclusionsThe Wtrd8/rd8 and Ctrp5+/-;rd8/rd8 mice raised on C57BL/6J did not develop early onset retinal changes that are characteristic of the rd8 phenotype, supporting the hypothesis that manifestation of rd8-associated pathology depends on the genetic background. The retinal pathology observed in mice with the Ctrp5+/-;wt/wt genotype is consistent with the L-ORD phenotype observed in patients and with the phenotype we described previously. The lack of rd8-associated retinal pathology in the Ctrp5+/-;wt/wt mouse model raised on the C57BL/6J background and the development of the L-ORD phenotype in these mice in the presence and absence of the rd8 mutation suggests that the pathology observed in the Ctrp5+/-;wt/wt mice is primarily associated with the S163R mutation in the Ctrp5 gene

    Sectoral R&D intensity and exchange rate volatility: a panel study for OECD countries

    Full text link
    A recent literature has pointed at potential negative effects of exchange rate volatility on innovation. In this paper, we propose that there may be a direct effect as well as an indirect effect via export activity. We test these hypotheses for sectoral R&D intensities using OECD panel data for manufacturing and services sectors for 14 OECD economies and the years 1987 - 2003. We find that the direct negative effect of volatility is pronounced in manufacturing sector but is dominated by the indirect effect via the export channel. Services do not face any effects of volatility on R&D intensities. While it is not clear which channel dominates our results confirm that there is a negative volatility affect related to openness on a sectoral level

    Data Traffic and Bandwidth Analysis

    Get PDF
    This paper tries to address current data and bandwidth problems by reorganizing few limitations of server-client and peer to peer communication model so that a hybrid model would solve issues related to both of them. The current infrastructure has some issues in catching up with the vastly increasing speeds and requirements of the clients. Following these trends, the existing infrastructure needs to be completely revamped in order to be successfully meeting the current requirements and also the requirements of the near future. Here arises a need to meet the current flow of demands while also buying time in order to get the new infrastructure in place. In order for that to happen, there exist some factors that can be manipulated so as to optimize the current system to meet the demands and provide a time buffer. Here these factors are researched upon and conclusions are drawn from this research so as to get the ways to manipulate and use these factors/resources in a correct manner for managing data traffic
    corecore