- Randomized QuickSort and Randomized Select Analysis - apr 04, 2015
I am a Ph.D. student in Computer Science and Engineering at The Ohio State University (OSU), advised by Dr. Xiaoyi Lu. My professional interests involve high-performance interconnects and protocols, erasure coding, and distributed systems. In my ongoing and recent projects, which are mainly developed in C++ and Java, I focus on implementing RDMA (Remote Direct Memory Access)-based communication protocols, optimizing I/O performance by exploiting RDMA for data transmission, enabling distributed systems to leverage heterogeneous hardware-optimized erasure coders in parallel, and designing tripartite graph based EC paradigm to gain better overlapping and parallelism on HPC clusters. In the meantime, I have participated in characterizing deep learning over big data stacks recently, and have understandings of deep learning training on distributed systems and modern data centers. Prior to graduate school, I worked as a Software Engineer at MiningLamp and Weibo, China. I finished my Bachelor’s degree in Tianjin University, China.
Graduate Research Associate
This project aims to implement and compare variant machine learning techniques for predicting house prices. It is an expanded project from Kaggle House Prices: Advanced Regression Techniques, such that the project is going to use the same dataset provided under this Kaggle competition. The machine learning techniques in this project include Linear Regression, Random Forest, Adaptive Boosting, Support Vector Regression, Gradient Boosted Decision Tree, K Nearest Neighbors, and Neural Network.
Trie is an ordered tree data structure which stores words in it so that users can search a word or a prefix quickly. Time complexity for adding a word to a Trie is $O(l)$, and for searching a word or a prefix is $O(l)$ too ($l$ is the length of the word or the prefix being added or searched). So it’s why we prefer Trie rather than Set and Hash Table in some situations, such as Dynamic Set, Associative Array and a predictive text or autocomplete Dictionary.
Though hash table is one of the most efficient data structures, it has some weaknesses.
Randomized QuickSort is an efficient sort algorithm requiring only $\Theta(n\log n)$ expected time on any input.
function RANDOMIZED-QUICKSORT(Array, low, high)
Randomized Select is an efficient algorithm to find $i$th smallest element of Array[low…high] with only linear expected time on any input.
function RANDOMIZED-SELECT(Array, low, high, i)