390 research outputs found
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
Use of dual-grating sensors formed by different types of fiber Bragg gratings for simultaneous temperature and strain measurements
We report on a systematic investigation of the dependence of both temperature and strain sensitivities on the fiber Bragg grating type, including the well-known Type I, Type IIA, and a new type that we have designated Type IA, using both hydrogen-free and hydrogenated B/Ge codoped fibres. We have identified distinct sensitivity characteristics for each grating type, and we have used them to implement a novel dual-grating, dual-parameter sensor device. Three dual-grating sensing schemes with different combinations of grating type have been constructed and compared, and that of a Type IA-Type IIA combination exhibits the best performance, which is also superior to that of previously reported grating-based structures. The characteristics of the measurement errors in such dual-grating sensor systems is also presented in detail. © 2004 Optical Society of America
Layer-refined Graph Convolutional Networks for Recommendation
Recommendation models utilizing Graph Convolutional Networks (GCNs) have
achieved state-of-the-art performance, as they can integrate both the node
information and the topological structure of the user-item interaction graph.
However, these GCN-based recommendation models not only suffer from
over-smoothing when stacking too many layers but also bear performance
degeneration resulting from the existence of noise in user-item interactions.
In this paper, we first identify a recommendation dilemma of over-smoothing and
solution collapsing in current GCN-based models. Specifically, these models
usually aggregate all layer embeddings for node updating and achieve their best
recommendation performance within a few layers because of over-smoothing.
Conversely, if we place learnable weights on layer embeddings for node
updating, the weight space will always collapse to a fixed point, at which the
weighting of the ego layer almost holds all. We propose a layer-refined GCN
model, dubbed LayerGCN, that refines layer representations during information
propagation and node updating of GCN. Moreover, previous GCN-based
recommendation models aggregate all incoming information from neighbors without
distinguishing the noise nodes, which deteriorates the recommendation
performance. Our model further prunes the edges of the user-item interaction
graph following a degree-sensitive probability instead of the uniform
distribution. Experimental results show that the proposed model outperforms the
state-of-the-art models significantly on four public datasets with fast
training convergence. The implementation code of the proposed method is
available at https://github.com/enoche/ImRec.Comment: 12 pages, 5 figure
The Practice of Basic Informatics 2020
Version 2020/04/02Kyoto University provides courses on 'The Practice of Basic Informatics' as part of its Liberal Arts and Sciences Program. The course is taught at many schools and departments, and course contents vary to meet the requirements of these schools and departments. This textbook is made open to the students of all schools that teach these courses. As stated in Chapter 1, this book is written with the aim of building ICT skills for study at university, that is, ICT skills for academic activities. Some topics may not be taught in class. However, the book is written for self-study by students. We include many exercises in this textbook so that instructors can select some of them for their classes, to accompany their teaching plans. The courses are given at the computer laboratories of the university, and the contents of this textbook assume that Windows 10 and Microsoft Office 2016 are available in these laboratories. In Chapter 13, we include an introduction to computer programming; we chose Python as the programming language because on the one hand it is easy for beginners to learn, and on the other, it is widely used in academic research. To check the progress of students' self-study, we have attached assessment criteria (a 'rubric') of this course as an Appendix. Current ICT is a product of the endeavors of many people. The "Great Idea" columns are included to show appreciation for such work. Dr. Yumi Kitamura and Dr. Hirohisa Hioki wrote Chapters 4 and 13, respectively. The remaining chapters were written by Dr. Hajime Kita. In revision for 2018 edition and after, Dr. Hiroyuki Sakai has participated in the author group, and Dr. Donghui Lin has also joined for English edition 2019. The authors hope that this textbook helps you to improve your academic ICT skill set. The content included in this book is selected based on the reference course plan discussed in the course development team for informatics at the Institute for Liberal Arts and Sciences. In writing this textbook, we obtained advice and suggestions from staffs of the Network Section, Information Infrastructure Division, Department of Planning and Information Management Department, Kyoto University on Chapters 2 and 3, from Mr. Sosuke Suzuki, NTT Communications Corporation also on Chapter 3, Rumi Haratake, Machiko Sakurai and Taku Sakamoto of the User Support Division, Kyoto University Library on Chapter 4. Dr. Masako Okamoto of Center for the Promotion of Excellence in Higher Education, Kyoto University helped us in revision of 2018 Japanese Edition. The authors would like to express their sincere gratitude to the people who supported them
Stable dual-wavelength oscillation of an erbium-doped fiber ring laser at room temperature
We propose a simple Er-doped fiber laser configuration for achieving stable dual-wavelength oscillation at room temperature, in which a high birefringence fiber Bragg grating was used as the wavelength-selective component. Stable dual-wavelength oscillation at room temperature with a wavelength spacing of 0.23nm and mutually orthogonal polarisation states was achieved by utilising the polarisation hole burning effect. An amplitude variation of less than 0.7dB over 80s period was obtained for both wavelengths
Hybrid-type fibre Bragg gratings and their applications
Fiber Bragg gratings (FBGs) have attracted a lot of attention in recent years due to their wide applications in optical telecommunications and smart sensing. They have been used as DWDM filters, dispersion compensators, gain flattening filters, optical switch and connection devices, and temperature/strain sensors. FBGs have been found to exhibit four different type structures according to their different growth mechanisms. Each type of FBG exhibits unique thermal and strain properties. Generally, the Type I gratings in hydrogenated and hydrogen-free fibers are used most for applications. However, some novel devices may be achieved by combinational structure of different types of gratings in the future. In this paper, we propose a novel concept of fabrication and application of FBGs with hybrid grating types. We have observed a complex growth behavior of a hybrid-type grating in the UV exposure to a B/Ge codoped fiber through a phase mask. A new model has been developed to simulate the complex growth behavior of the hybrid-type gratings, giving results in excellent agreement with experiment
Amidine-Mediated Zwitterionic Ring-Opening Polymerization of N-Alkyl N-Carboxyanhydride: Mechanism, Kinetics, and Architecture Elucidation
© 2016 American Chemical Society. Zwitterionic ring-opening polymerization (ZROP) of N-butyl N-carboxyanhydrides (Bu-NCAs) has been investigated using 1,8-diazabicycloundec-7-ene (DBU), a bicyclic amidine initiator. It was found that poly(N-butylglycine)s (PNBGs) with molecular weight (Mn) in the 3.5-32.4 kg mol-1 range and polydispersity index (PDI) in the 1.02-1.12 range can be readily obtained by systematically varying the initial monomer to initiator feed ratio. The polymerization exhibits characteristics of a controlled polymerization, as evidenced by the linear increase of polymer molecular weight with conversion and the successful enchainment experiments. Kinetic studies revealed that the reaction is first-order dependent on the monomer and the DBU concentration. The rate of initiation is comparable to that of the propagation. Random copolypeptoids of poly[(N-propargylglycine)-r-(N-butylglycine)]s [P(NPgG-r-NBG)s] were also synthesized by DBU-mediated copolymerization of Bu-NCA and N-propargyl N-carboxyanhydride (Pg-NCA). Subsequent grafting with azido-terminated poly(ethylene glycol) (PEG) produces bottlebrush copolymers. Analysis of bottlebrush copolymer samples using atomic force microscopy (AFM) revealed a surface morphology of toroid-shaped nanostructures, consistent with the polypeptoid backbone having cyclic architecture. Small-angle neutron scattering (SANS) characterization of the bottlebrush polymer ensemble in solution also confirms the cyclic architecture of the polypeptoid backbones
A modified J model for efficiently calculating the electromagnetic fields of ReBCO no-insulation pancake coils using an explicit-implicit hybrid algorithm
Rare-earth (Re)Ba2Cu3O7-x (ReBCO) no-insulation (NI) coil is widely concerned
due to its excellent electromagnetic and thermal properties. However, the
presence of the turn-to-turn shunts in NI coils leads to that complexity of
numerical simulation is increased. In this paper, a modified J model is
proposed and the corresponding explicit-implicit hybrid algorithm is designed
to calculate NI coils. The numerical results are in good agreement with the
experimental data and the circuit model. The homogenization model is also
proposed to simulate the large-scale NI coils in the background magnets. The
modified J model has good accuracy and fast calculation speed, which can also
be used to solve electromagnetic fields of insulation coils efficiently
Glassy carbon electrode modified with 7,7,8,8-tetracyanoquinodimethane and graphene oxide triggered a synergistic effect: low-potential amperometric detection of reduced glutathione.
A sensitive electrochemical sensor based on the synergistic effect of 7,7,8,8-tetracyanoquinodimethane (TCNQ) and graphene oxide (GO) for low-potential amperometric detection of reduced glutathione (GSH) in pH 7.2 phosphate buffer solution (PBS) has been reported. This is the first time that the combination of GO and TCNQ have been successfully employed to construct an electrochemical sensor for the detection of glutathione. The surface of the glassy carbon electrode (GCE) was modified by a drop casting using TCNQ and GO. Cyclic voltammetric measurements showed that TCNQ and GO triggered a synergistic effect and exhibited an unexpected electrocatalytic activity towards GSH oxidation, compared to GCE modified with only GO, TCNQ or TCNQ/electrochemically reduced GO. Three oxidation waves for GSH were found at −0.05, 0.1 and 0.5 V, respectively. Amperometric techniques were employed to detect GSH sensitively using a GCE modified with TCNQ/GO at −0.05 V. The electrochemical sensor showed a wide linear range from 0.25 to 124.3 μM and 124.3 μM to 1.67 mM with a limit of detection of 0.15 μM. The electroanalytical sensor was successfully applied towards the detection of GSH in an eye drop solution
Consistency analysis in multi-language knowledge sharing system
Unprecedented growth in knowledge sharing among multi-language communities, both common and distinct languages, has raised the possibility of sharing inconsistent content. Though popular with traditional system, the approach to explicitly state consistency rules to avoid inconsistency is practically not suited for multi-language knowledge sharing system because of sheer complexity. Alternatively this chapter focuses on potential cause of inconsistency, cases such as content omitted, content updates not propagated and content conflicts. Ignoring such cases in knowledge sharing has undesirable consequences: community bias, global and local inconsistency and regional discrepancies. Consistency constraints from opposing knowledge sharing goals among communities is another issue. Due to which consistency policy ranges from rigid ‘one to one consistency’ to non-rigid ‘consistency where needed’. This chapter contributes with (a) process-based approach for multilingual content synchronization to leverage knowledge equally and (b) propagation-based approach to analyze community preferences when sharing specific content categories/geographic regions, to customize knowledge sharing; a value add-on to designing language services adhering to knowledge sharing goals. © 2018, Springer Nature Singapore Pte Ltd
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