2024/3/14（木）

Understand Text in Scene Images: Challenges and Recent Approaches

Scene text understanding is the task of detecting and recognizing text in natural images, such as street signs, billboards, product labels, etc. It is a challenging problem because of numerous factors. Text in natural images can have various fonts, sizes, colors, styles, and orientations. Some text may be curved, distorted, or partially occluded by other objects. Text may also appear in different languages or scripts, which require different recognition methods. Images captured in natural scenes may suffer from noise, blur, low resolution, uneven illumination, or complex backgrounds. To address these challenges, researchers have proposed various methods based on handcrafted features, deep learning, or hybrid approaches. Some methods focus on improving the text detection performance, while others aim to enhance the text recognition accuracy. Some methods also attempt to solve the end-to-end scene text understanding problem, which integrates both detection and recognition in a single framework. However, there is still room for improvement and innovation in this field, as the current methods still struggle with some difficult cases. In the talk titled “Understand Text in Scene Images: Challenges and Recent Approaches," the speaker will delve into scene text recognition. The talk will commence with an introduction to the concept of scene text detection and recognition in images, elucidating the primary challenges encountered in this field. The speaker goes over the most recent strategies that have been created to get over these obstacles. The speaker will discuss his recent work on scene text detection and recognition using domain adaptation techniques and other findings on the problem in the latter portion of the talk.

2022/12/16（金）

Broadband Dielectric Spectroscopy as a Powerful Tool for Investigating Molecular Dynamics and Proton Reaction Kinetics of Condensed Matter Systems

　Broadband Dielectric Spectroscopy, BDS, is a powerful experimental technique developed to measure dielectric response of a condensed matter systems in a very wide frequency range, typically spanning from 1mHz to 100 GHz. In this presentation we will provide an exhaustive survey of the recent advances in the study of the molecular dynamics behavior of various glass-forming liquids (van der Waals, H-bonded, polymers, etc.) at different thermodynamic conditions as well as under confinement at the nanoscale by means of BDS. Moreover, we will demonstrate and discuss how dielectric spectroscopy can be successfully used to monitor kinetics of chemical equilibration process related to tautomerisation and mutarotaion phenomena observed in pharmaceuticals, saccharides and biological materials.

2019/4/4(木)

Electronic properties of electronic materials: interfaces & doping

Electronic and opto-electronic devices used in information, communication, energy conversion, and energy storage technologies rely on a precise control of the charge density distribution, which is the key parameter for a wide range of electronic and optical processes in devices. The charge density and its energy spectrum in electronic materials determine elemental parameters and functions, such as the Fermi level position, type and mobility of charge carriers, interfacial energy level alignment, carrier injection and extraction at contacts, and the characteristics of excitations. The primary conventional method to control the charge density in electronic materials is doping, as already employed by Shockley, Bardeen, and Brattain in the first transistors in the 1940s. However, established electronic materials and doping concepts, e.g., the statistical incorporation of dopant atoms in a covalent lattice, will soon reach fundamental limits. The anticipated route beyond this deadlock is the use of new electronic materials and combinations thereof, where tuning quantum confinement, dimensionality, and the charge density enable new device concepts. In this contribution, at first the fundamental differences in the electronic properties of selected advanced and emerging electronic materials are contrasted, i.e., organic semiconductors, metal halide perovskites, and two-dimensional (2D) transition metal dichalcogenide (TMDC) monolayers. Next, considerations of how the energy levels differ in practical thin films from those in single crystals will provide the basis for discussing fundamental interfacial phenomena in hybrid heterostructures comprising dissimilar material classes. Modern approaches to tune the interfacial charge density re-arrangement, and concomitantly the energy level alignment, will then be introduced and their impact on interface functionality in devices exemplified. Most of these approaches are based on employing very strong molecular electron donor or acceptor molecules as interlayers, and photochromic molecular switches even facilitate operando optical control over electrical device characteristics, i.e., multifunctionality.