I have great enthusiasm for theoretical computer science, especially computational complexity. Currently I'm working on *approximate degrees*, *circuit lower bounds*, and *pseudorandomness* advised by Prof. Emanuele Viola. I visited the Simons Institute for the "Lower Bounds in Computational Complexity" program last fall.

Previously I earned my bachelor's and master's degrees from Shanghai Jiao Tong University, advised by Prof. Yijia Chen. During that period, I did research on parameterized complexity, circuit complexity, and descriptive complexity. I love to explore a wide range of research topicsI had done some research work on correlation decay, recursion theory, and equivalence checking. I also have some interest in principles of programming languages, especially type theory., to learn some latest big results/frameworks, and to attack challenging open problems.

## Papers

- Slicewise Definability in First-Order Logic with Bounded Quantifier Rank
- with Yijia Chen and Joerg Flum, 26th EACSL Annual Conference on Computer Science Logic (CSL 2017)
- manuscript, conference version
- Using color-coding we demonstrate that some parameterized (hyper)graph problems can be slicewise-defined in $\mathrm{FO}_q$ where $q$ is independent of the parameter $k$, and prove the strictness of $\big(\mathrm{XFO}_{q} \big)_{q \in \mathbb{N}}$ by proving that $\mathrm{FO}_{q} \subsetneq \mathrm{FO}_{q+1}$ on arithmetical structures for every $q\in \mathbb{N}$

- Algorithm for Relatively Small Planted Clique with Small Edge Probability
- Single author, in Chinese, Journal of Shanghai Jiao Tong University, 2017, 51(10)
- introductory slides,
~~Chinese manuscript~~Unfortunately due to rights restriction, I cannot put my Chinese manuscript here, English draft - Using the generalized planted model $\mathcal{G}(n, p(n), k(n))$, we extend the analysis in the paper of Feige and Ron to the cases where $p(n) = o(1)$ but not-that-smallIf we write $p(n)$ as $p(n) = n^{-\alpha(n)}$, then we require $\lim_{n \to \infty} \alpha(n) = 0$. (otherwise the problem becomes trivial), proving that in such cases we can find the planted clique of size $\Theta(\sqrt{n \cdot p(n) \cdot (1-p(n))}) = o(\sqrt{n})$
- This result is a by-product of my research on
*circuit lower bounds*for generalized planted clique problem against $\mathrm{AC}^0[p]$

- Ladner Theorem in Parameterized Complexity Theory
- Undergraduate Thesis, supervised by Prof. Yijia Chen, 2014
- We use finite injury priority method to prove that there are infinitely many $\mathrm{W[1]}$ problems that are neither $\mathrm{W[1]}$-Complete nor $\mathrm{FPT}$ if $\mathrm{FPT} \neq \mathrm{W[1]}$, presenting a "complete" proof which is more accessible to people not well-versed in recursion theory, compared with the original proof by Downey and Fellows

## Academic Activities

### Talks Given

2017 | Autumn | Special Topics in Complexity Theory |

Foundations of Cryptography | ||

Spring | Master's Thesis Defense | |

2016 | Spring | Master's Thesis Openning Defense |

2015 | Autumn | Holographic Algorithms and Counting Complexity |

Spring | Communication Complexity | |

2014 | Autumn | Advanced Topics on Computational Compleixty |

Summer | Finite Injury Method | |

Spring | Kolmogorov Complexity |

### Summer Schools, Conferences, and Workshops Participated

2018 | Feb. | Workshop on Probabilistic and Extremal Combinatorics, Harvard |

Jan. | Innovations in Theoretical Computer Science, MIT | |

2017 | Nov. | Workshop on Algebraic Methods in Combinatorics, Harvard |

Oct. | Workshop on Additive Combinatorics, Harvard | |

July | Swedish Summer School in Computer Science, KTH | |

2016 | Aug. | China Theory Week, CUHK |

Summer School on Quantum Algorithms and Quantum Programming, GZU | ||

July | Coalgebraic Methods for Automata, ECNU | |

Highlights of Theoretical Computer Science, SHUFE | ||

May | Chinese Mathematical Logic Conference, Fudan | |

2015 | Aug. | China Theory Week, SJTU |

July | Logic Summer School in China, ZNU | |

2014 | Aug. | BASICS Summer School and Logic Summer School in China, SJTU |

June | IMS Graduate Summer School in Logic, NUS | |

May | Annual Meeting of Asian Association for Algorithms and Computation, ZJU | |

2013 | Sept. | Asian Logic Conference, SYSU |

Aug. | Summer School on Verification on Infinite State Systems, SJTU | |

July | Asian Initiative for Infinity (AII) Graduate Summer School, NUS |

### Teaching Assistantships

2018 | Summer | CS 4800 Algorithms, Northeastern, for undergraduates |

2016 | Summer | Theory of Computation, Fudan, for undergraduates |

2015 | Summer | Advanced Algorithms, Fudan, for graduates |

Spring | Formal Semantics of Programming Languages, SJTU, for graduates | |

2014 | Summer | Advanced Algorithms, Fudan, for graduates |

2013 | Winter | Algorithms, SJTU, for undergraduates |

## Boring Stuff

- Born and grown up in Swatow, I'm very proud to be TeochewI don't identify myself as general Chinese. For ambiguities of the term "Chinese", see this paper . I can speak TeochewTeochew is also very different from Mandarin Chinese., Cantonese, Madarin Chinese, English, and some French.
- I love painting. Here are some of my paintings(Gouache, Chinese Painting) in my early years:
*1*,*2*,*3*,*4*,*5*,*6*,*7*,*8*(However, as you can see, I'm not good at Chinese Calligraphy); some handcraftings:*1*,*2*. - I have been a fan of
*Jamie Oliver*since secondary school: thanks to TVB Pearl, I watched the interesting*Oliver's Twist*TV show. - I used to be very active in programming contests in my secondary schools. I had won first prizes in NOIp for four times.
- In 2011, together with two teammates I built an automative model racing car, using mini camera to capture image of the track and microprocessor to process and control the car: photo, source codesIDE: CodeWarrior for DSC56800E v8.3

MCU+DSP: MC56F8366

TVP5146, SN74V235, BTS7960, MAX6954, etc., utility programs(C, Python), report(in Chinese), video 1, 2; I took full responsibility for the final drifting! - In 2012, based on TORCS(The Open Racing Car Simulator), I developed CyberTORCS, an educational intelligent vehicles simulation platform with pending systems for car racing, car chasing, and car parking: release version, report(in Chinese).

## Boring Links

A bad day writing code in Scheme is better than a good day writing code in C.

by*David Stigant*, spread by*Matthias Felleisen*- Graphical Linear Algebra, The Logic Blog front-end
- Lisp Machine, Lisp Machine Manual, Symbolics, Stack Computers, Homebrew Computers
- Oskar's Puzzles
- It's Robot Fighting Time! 3,2,1,Activate! Robomaster
- My Correct Views on Everything
- A Time for Choosing