Page History: Yang Yu @ NJUCS

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Page Revision: 2013/11/25 14:19


ImageChinese name
Yang Yu (Y. Yu)
Can be pronounced as "young you"
Ph.D., Assistant Researcher
LAMDA Group
Department of Computer Science
National Key Laboratory for Novel Software Technology
Nanjing University
Office: 919, Computer Science Building, Xianlin Campus

email: , , (the last email is both symbolic and problematic)
Image Image

I received my Ph.D. degree in Computer Science from Nanjing University in 2011 (supervisor Prof. Zhi-Hua Zhou), and then joined the Department of Computer Science and Technology of Nanjing University as an assistant researcher in 2011.

I am interested in artificial intelligence, particularly, evolutionary computation and machine learning. I have published papers in conferences (e.g. IJCAI) and journals (e.g. Artificial Intelligence), and won several awards such as Grand Champion (with other LAMDA members) of PAKDD'06 Data Mining Competition, the best paper award of PAKDD'08, the best theory paper award of GECCO'11, and China Computer Federation Outstanding Doctoral Dissertation Award in 2011.

(Detailed CV)

Research

I am interested in investigating towards the goal of artificial intelligence. As conceived by Alan Turing, one possible way of building an intelligent machine is to evolve learning machines, which now drops into multiple subfields of artificial intelligence, especially machine learning and evolutionary computation. Currently I am focusing on the subfields:
  • Theoretical foundation of evolutionary algorithms (my related publications): to understand and reveal the power of evolutionary algorithms;
  • Ensemble learning (my related publications): to achieve the strongest generalization ability from finite samples;
  • Learning agent (my related publications): to be intelligent to survive in environments autonomously.

Selected work: (full publication list)
  • General approaches to running time analysis of metaheuristic optimization algorithms: (with Chao Qian and Zhi-Hua Zhou)
    The running time, or the computational complexity, of evolutionary algorithms and other metaheuristic algorithms is one of the most important theoretical issues to understand these algorithms.
    • We developed the convergence-based approach (PDF-aij08) that can be applied to obtain running time bounds of a large range of metaheuristic algorithms.
    • By comparing two algorithms, we developed a new analysis tool, switch analysis (tr11|PDF-ppsn10) that can lead to tighter running time bounds.
      • Using switch analysis to compare problem instances, we can identify the hardest and the easiest problem instances for a metaheuristic algorithm in a problem class (PDF-ppsn12).

  • Approximation ability of evolutionary optimization: (with Xin Yao and Zhi-Hua Zhou)
    Evolutionary algorithms are most commonly used to obtain good-enough solutions rather than optimal solutions in practice, which relates to their approximation ability. We developed the SEIP framework (PDF-aij12) to characterize the approximation ability of evolutionary algorithms, and showed that they can achieve the currently best-achievable approximation ratio for the k-set cover problem, which also reveals the advantage of evolutionary algorithms over the well known greedy algorithm.

  • The role of diversity in ensemble learning (with Nan Li, Yu-Feng Li and Zhi-Hua Zhou)
    Ensemble learning is a machine learning paradigm that achieves the state-of-the-art performance. Diversity was believed to be a key to a good performance of an ensemble approach, which, however, previously served only as a heuristic idea.
    • By the diversity regularized machine (PDF-ijcai11/code), we showed that diversity plays a role of regularization as in popular statistical learning approaches.
    • We proved that diversity defined on hypothesis output space plays a role of regularization, and proposed the diversity regularized ensemble pruning to prune Bagging classifiers. (PDF-ecml12/code)

(My Goolge Scholar Citations)

Recent Professional Activities


Teaching

  • Data Mining. (for M.Sc. students. Fall, 2013) >>>Class Pages>>>
  • Introduction to Data Mining. (for undergraduate students. Spring, 2013)
  • Digital Image Processing. (for undergraduate students. Spring, 2013)
  • Data Mining. (for M.Sc. students. Fall, 2012)
  • Introduction to Data Mining. (for undergraduate students. Spring, 2012)
  • (Assistant) Data mining. (for graduate students. Fall, 2007) Teaching Assistant Page
  • (Assistant) Algorithm Design and Analysis. (for undergraduate students. Fall, 2005)



Mail:
National Key Laboratory for Novel Software Technology, Nanjing University, Xianlin Campus Mailbox 603, 163 Xianlin Avenue, Qixia District, Nanjing 210023, China
(In Chinese:) 南京市栖霞区仙林大道163号,南京大学仙林校区603信箱,软件新技术国家重点实验室,210023。

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