Zero-Shot Recognition using Dual Visual-Semantic Mapping Paths

Zero-shot recognition aims to accurately recognize objects of unseen classes by using a shared visual-semantic mapping between the image feature space and the semantic embedding space. This mapping is learned on training data of seen classes and is expected to have transfer ability to unseen classes. In this paper, we tackle this problem by exploiting the intrinsic relationship between the semantic space manifold and the transfer ability of visual-semantic mapping. We formalize their connection and cast zero-shot recognition as a joint optimization problem. Motivated by this, we propose a novel framework for zero-shot recognition, which contains dual visual-semantic mapping paths. Our analysis shows this framework can not only apply prior semantic knowledge to infer underlying semantic manifold in the image feature space, but also generate optimized semantic embedding space, which can enhance the transfer ability of the visual-semantic mapping to unseen classes. The proposed method is evaluated for zero-shot recognition on four benchmark datasets, achieving outstanding results.Comment: Accepted as a full paper in IEEE Computer Vision and Pattern Recognition (CVPR) 201

K-nearest Neighbor Search by Random Projection Forests

K-nearest neighbor (kNN) search has wide applications in many areas, including data mining, machine learning, statistics and many applied domains. Inspired by the success of ensemble methods and the flexibility of tree-based methodology, we propose random projection forests (rpForests), for kNN search. rpForests finds kNNs by aggregating results from an ensemble of random projection trees with each constructed recursively through a series of carefully chosen random projections. rpForests achieves a remarkable accuracy in terms of fast decay in the missing rate of kNNs and that of discrepancy in the kNN distances. rpForests has a very low computational complexity. The ensemble nature of rpForests makes it easily run in parallel on multicore or clustered computers; the running time is expected to be nearly inversely proportional to the number of cores or machines. We give theoretical insights by showing the exponential decay of the probability that neighboring points would be separated by ensemble random projection trees when the ensemble size increases. Our theory can be used to refine the choice of random projections in the growth of trees, and experiments show that the effect is remarkable.Comment: 15 pages, 4 figures, 2018 IEEE Big Data Conferenc

Interpreters as historians in China

Subsequent to the western effort in researching the history of interpreting, Chinese scholars have also shown initial interest in the subject. Since China has always valued the recording of history, it seems that historical resources would offer the data required for such an investigation. Interestingly, some historical data relating to interpreting events seem to display a regular linguistic device: the use of dialogues to document exchanges between Chinese and foreign envoys. According to Li Nanqiu (2002), this observation suggests that interpreters’ words were put down in writing as part of historical records. Such a claim, however, is not entirely conclusive. Based on examples drawn from primary historical records, this article analyzes discourse features of historical records of interpreting events, and shows the possible role of interpreters as historians, or consultants, in the recording of history in the early diplomatic history of China. À la suite des efforts réalisés par les chercheurs occidentaux en histoire de l’interprétation, les chercheurs chinois commencent à s’intéresser à ce sujet. La Chine ayant toujours accordé une grande importance aux archives, les ressources historiques nécessaires à une telle recherche ne manquent pas. Il est intéressant d’observer que certaines données historiques liées à l’interprétation laissent apparaître une tendance linguistique régulière : la compilation de dialogues échangés entre envoyés chinois et étrangers. D’après Li Nanqiu (2002), les interventions des interprètes ont été retranscrites pour faire partie des archives historiques. S’appuyant sur des exemples extraits d’archives primaires, cet article analyse les discours d’événements interprétés, et montre le rôle des interprètes en tant qu’historiens, ou consultants, dans la compilation d’archives historiques dès les débuts de l’histoire diplomatique en Chine

MBE GROWTH AND CHARACTERIZATION OF Pb-SALT SEMICONDUCTORS FOR MID-INFRARED DETECTOR AND LASER APPLICATION

IV-VI semiconductors grown by molecular beam epitaxy (MBE) on various substrates are extensively attractive for mid-infrared optoelectronic device application. The main goal of this research is to improve device performance by lowering defects densities in the epitaxial layers during MBE growth of Pb-salt materials on a lattice-mismatched substrate. Most of the work is based on MBE growth of monocrystalline PbSe on Si (111) substrates. Details of experiments are described and supported by reflection high-energy electron diffraction (RHEED) patterns. The effect of the in-situ surface treatment methods with a motivation of improving electrical and morphological properties of epilayers is demonstrated.A detailed study on surface morphologies and chemical composition of growth pits and dislocations in PbSe epilayers is provided. Various growth defects are investigated by scanning electron microscopy (SEM) and energy-dispersive x-ray analysis (EDXA). Through a series of experimental studies, it has been confirmed that the vast majority of growth pits within PbSe epilayers contains either single or multiple PbSe microcrystals with a distinct cuboid shape.Lead salt mid-infrared optoelectronic devices are fabricated on various substrates. Several other research works include: (1) Edge-emitting infrared lasers on BaF2 (110) substrates. A method of substrate transfer from a BaF2 substrate to a copper heat-sink is developed. Pulsed photoluminescence (PL) measurements are conducted with help of Fourier transform infrared (FTIR) spectroscopy method during every single step of device processing. (2) Mid-infrared detectors on silicon (111) substrates. Single-element PbSnSe infrared detectors have been made on CaF2 /Si (111) heterostructures; I-V measurement is accomplished on these detectors