The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Ashvin Vishwanath - One of the best experts on this subject based on the ideXlab platform.
-
dirac fermions in solids from high tc cuprates and graphene to topological insulators and weyl semimetals
Annual Review of Condensed Matter Physics, 2014Co-Authors: Oskar Vafek, Ashvin VishwanathAbstract:Understanding Dirac-like fermions has become an imperative in modern condensed matter sciences: All across the Research Frontier, from graphene to high Tc superconductors to the topological insulators and beyond, various electronic systems exhibit properties that can be well described by the Dirac equation. Such physics is no longer the exclusive domain of quantum field theories and other esoteric mathematical musings; instead, physics of real condensed matter systems is governed by such equations, and important materials science and practical implications hinge on our understanding of Dirac particles in two and three dimensions. Although the physics that gives rise to the massless Dirac fermions in each of the above-mentioned materials is different, the low-energy properties are governed by the same Dirac kinematics. The aim of this article is to review a selected cross-section of this vast field by highlighting the generalities and contrasting the specifics of several physical systems.
-
dirac fermions in solids from high tc cuprates and graphene to topological insulators and weyl semimetals
arXiv: Mesoscale and Nanoscale Physics, 2013Co-Authors: Oskar Vafek, Ashvin VishwanathAbstract:Understanding Dirac-like Fermions has become an imperative in modern condensed matter sciences: all across its Research Frontier, from graphene to high T$_c$ superconductors to the topological insulators and beyond, various electronic systems exhibit properties which can be well described by the Dirac equation. Such physics is no longer the exclusive domain of quantum field theories and other esoteric mathematical musings; instead, real physics of real systems is governed by such equations, and important materials science and practical implications hinge on our understanding of Dirac particles in two and three dimensions. While the physics that gives rise to the massless Dirac Fermions in each of the above mentioned materials is different, the low energy properties are governed by the same Dirac kinematics. The aim of this article is to review a selected cross-section of this vast field by highlighting the generalities, and contrasting the specifics, of several physical systems.
Marios M Polycarpou - One of the best experts on this subject based on the ideXlab platform.
-
ant colony optimization algorithms for dynamic optimization a case study of the dynamic travelling salesperson problem Research Frontier
IEEE Computational Intelligence Magazine, 2020Co-Authors: Michalis Mavrovouniotis, Shengxiang Yang, Mien Van, Marios M PolycarpouAbstract:Ant colony optimization is a swarm intelligence metaheuristic inspired by the foraging behavior of some ant species. Ant colony optimization has been successfully applied to challenging optimization problems. This article investigates existing ant colony optimization algorithms specifically designed for combinatorial optimization problems with a dynamic environment. The investigated algorithms are classified into two frameworks: evaporation-based and population-based. A case study of using these algorithms to solve the dynamic traveling salesperson problem is described. Experiments are systematically conducted using a proposed dynamic benchmark framework to analyze the effect of important ant colony optimization features on numerous test cases. Different performance measures are used to evaluate the adaptation capabilities of the investigated algorithms, indicating which features are the most important when designing ant colony optimization algorithms in dynamic environments.
Eduard Hovy - One of the best experts on this subject based on the ideXlab platform.
-
emotion recognition in conversation Research challenges datasets and recent advances
IEEE Access, 2019Co-Authors: Soujanya Poria, Navonil Majumder, Rada Mihalcea, Eduard HovyAbstract:Emotion is intrinsic to humans and consequently, emotion understanding is a key part of human-like artificial intelligence (AI). Emotion recognition in conversation (ERC) is becoming increasingly popular as a new Research Frontier in natural language processing (NLP) due to its ability to mine opinions from the plethora of publicly available conversational data on platforms such as Facebook, Youtube, Reddit, Twitter, and others. Moreover, it has potential applications in health-care systems (as a tool for psychological analysis), education (understanding student frustration), and more. In Addition, ERC is also extremely important for generating emotion-aware dialogues that require an understanding of the user's emotions. Catering to these needs calls for effective and scalable conversational emotion-recognition algorithms. However, it is a difficult problem to solve because of several Research challenges. In this paper, we discuss these challenges and shed light on recent Research in this field. We also describe the drawbacks of these approaches and discuss the reasons why they fail to successfully overcome the Research challenges in ERC.
-
emotion recognition in conversation Research challenges datasets and recent advances
arXiv: Computation and Language, 2019Co-Authors: Soujanya Poria, Navonil Majumder, Rada Mihalcea, Eduard HovyAbstract:Emotion is intrinsic to humans and consequently emotion understanding is a key part of human-like artificial intelligence (AI). Emotion recognition in conversation (ERC) is becoming increasingly popular as a new Research Frontier in natural language processing (NLP) due to its ability to mine opinions from the plethora of publicly available conversational data in platforms such as Facebook, Youtube, Reddit, Twitter, and others. Moreover, it has potential applications in health-care systems (as a tool for psychological analysis), education (understanding student frustration) and more. Additionally, ERC is also extremely important for generating emotion-aware dialogues that require an understanding of the user's emotions. Catering to these needs calls for effective and scalable conversational emotion-recognition algorithms. However, it is a strenuous problem to solve because of several Research challenges. In this paper, we discuss these challenges and shed light on the recent Research in this field. We also describe the drawbacks of these approaches and discuss the reasons why they fail to successfully overcome the Research challenges in ERC.
Oskar Vafek - One of the best experts on this subject based on the ideXlab platform.
-
dirac fermions in solids from high tc cuprates and graphene to topological insulators and weyl semimetals
Annual Review of Condensed Matter Physics, 2014Co-Authors: Oskar Vafek, Ashvin VishwanathAbstract:Understanding Dirac-like fermions has become an imperative in modern condensed matter sciences: All across the Research Frontier, from graphene to high Tc superconductors to the topological insulators and beyond, various electronic systems exhibit properties that can be well described by the Dirac equation. Such physics is no longer the exclusive domain of quantum field theories and other esoteric mathematical musings; instead, physics of real condensed matter systems is governed by such equations, and important materials science and practical implications hinge on our understanding of Dirac particles in two and three dimensions. Although the physics that gives rise to the massless Dirac fermions in each of the above-mentioned materials is different, the low-energy properties are governed by the same Dirac kinematics. The aim of this article is to review a selected cross-section of this vast field by highlighting the generalities and contrasting the specifics of several physical systems.
-
dirac fermions in solids from high tc cuprates and graphene to topological insulators and weyl semimetals
arXiv: Mesoscale and Nanoscale Physics, 2013Co-Authors: Oskar Vafek, Ashvin VishwanathAbstract:Understanding Dirac-like Fermions has become an imperative in modern condensed matter sciences: all across its Research Frontier, from graphene to high T$_c$ superconductors to the topological insulators and beyond, various electronic systems exhibit properties which can be well described by the Dirac equation. Such physics is no longer the exclusive domain of quantum field theories and other esoteric mathematical musings; instead, real physics of real systems is governed by such equations, and important materials science and practical implications hinge on our understanding of Dirac particles in two and three dimensions. While the physics that gives rise to the massless Dirac Fermions in each of the above mentioned materials is different, the low energy properties are governed by the same Dirac kinematics. The aim of this article is to review a selected cross-section of this vast field by highlighting the generalities, and contrasting the specifics, of several physical systems.
Waiyeung Wong - One of the best experts on this subject based on the ideXlab platform.
-
recent design tactics for high performance white polymer light emitting diodes
Journal of Materials Chemistry C, 2014Co-Authors: Xiaolong Yang, Waiyeung Wong, Guijiang ZhouAbstract:White polymer light-emitting diodes (WPLEDs) represent an intense Research subject towards their potential applications in full-color displays, next-generation solid-state lighting sources and back-lighting of liquid-crystal displays due to their merits including low-cost fabrication, flexibility, large area and ease of construction etc. Unfortunately, WPLEDs generally show much poorer EL performance with respect to those made by the vacuum deposition strategy owing to the inherent disadvantages associated with the materials used, device structures and device fabrication processes etc., which has seriously restricted their practical applications. However, the performances of WPLEDs have been improved greatly in recent years, and can even realize some practical devices. In this review, the critical design tactics employed to achieve this goal are presented, which include developing high performance functional light emitters, maintaining a good charge injection/transport balance, introducing new functional layer, surface morphology engineering and employing novel device construction processes etc. In addition, the ongoing challenges and future perspectives of this Research Frontier are also highlighted.
-
luminescent organometallic poly aryleneethynylene s functional properties towards implications in molecular optoelectronics
Dalton Transactions, 2007Co-Authors: Waiyeung WongAbstract:This article highlights recent progress in the development of rigid-rod metallopolyyne polymers of late transition metals which can exhibit easily tunable luminescent and electronic properties. Considerable focus is placed on the design strategies towards the tuning capability of phosphorescence emission color and optical bandgap of this class of luminescent metallopolymers, and the evaluation of their suitability as emitters in light-emitting applications, optical power limiters for sensor protection and semiconductors in organometallic photovoltaic cells. An effective approach based on structural modification of the spacer group can be devised to achieve the full-color phosphorescence emission spanning almost the whole visible spectrum and to tune the material properties of these functional organometallic polymers. The major advances, ongoing challenges and future perspectives of this Research Frontier are also discussed.