Posts by Category

GMM for EM-algorithm

45 minute read

unsupervised problem for EM algorithm, especially gaussian mixture model.

Heap and Priority Queue Analysis and Practice using python

50 minute read

How to use and implement heap and priority queue using python

Dijkstra Algorithm in Python

41 minute read

Implementaiton and Description of Dijkstra Algorithm

Floyd Warshall Algorithm in Python

37 minute read

All pair shortest paths algorithm

Bellman-Ford and DAG Algorithms in Python

28 minute read

Single source shortest path Algorithm

나무 재테크

15 minute read

주어진 조건에 따라 시뮬레이션 하는 문제, 적절한 자료구조 사용

인구이동

17 minute read

Union Find을 사용하여 시뮬레이션 해보는 알고리즘

낚시왕

26 minute read

상어 클래스를 만들고, 이를 배열에 넣어 다루는 연습, 시뮬레이션

드래곤 커브

23 minute read

규칙성을 찾고 이를 바탕으로 DFS 연습

치킨배달

4 minute read

조합에 대한 경우의 수 탐색하는 연습

아기상어

15 minute read

우선순위에 따른 BFS 연습을 하기 좋은 문제

이차원배열과 연산

15 minute read

행 연산과, 열 연산 연습

감시

42 minute read

DFS, backtracking, or pruning practice

사다리조작

72 minute read

DFS, backtracking, or pruning practice

스타트와 링크

20 minute read

팀 나누기, DFS, combination 연습

경사로

11 minute read

simulation practice

톱니바퀴

23 minute read

DFS, rotate practice

How to implement Permutation in python

6 minute read

A practice to implmentation of permutation.

연산자 끼워넣기

5 minute read

DFS practice

바이러스

14 minute read

바이러스의 전파를 막기 위해 DFS를 사용하여 최소화하는 벽을 세워보자

테트로미노

14 minute read

주어진 조건에 맞추어 테트리스를 활용한 문제를 풀어보자

로봇 청소기

33 minute read

주어진 조건에 맞게 구현

퇴사

16 minute read

DFS, DP를 이용하여 문제 풀이 연습

GCD 와 LCD 구하기

2 minute read

최대공약수, 최소공배수를 구해라

시험감독

1 minute read

코딩 테스트 연습

주사위 굴리기

9 minute read

주사위와 회전을 구현해보자.

뱀- 구현능력점검

43 minute read

시뮬레이션을 구현할 수 있나 테스트, queue의 사용연습

2048(Easy)

32 minute read

queue의 사용과 DFS 연습, 삼성 역량 테스트

79.Word Search

49 minute read

Given a 2D board and a word, find if the word exist in the grid: backtracking, pruning practice.

Find Top K sth

17 minute read

sorting and heap usage practice

프로세서 연결하기

31 minute read

삼성sw 역량 테스트 문제. 가능한 프로세서를 모두 연결시키되필요한 최소전선수를 찾아라

구슬탈출2

41 minute read

samsung sw test practice, DFS and BFS practice

1315.Sum of Nodes with Even-Valued Grandparent

8 minute read

practice of DFS

218.The Skyline Problem

9 minute read

Practice of divide and conquer, heap.

Find Prime Factors

3 minute read

how to find prim factors

1319.Number of Operations to Make Network Connected

9 minute read

practice of disjoint set

200.Number of Islands

12 minute read

practice of DFS and union find

1254.Number of Closed Island

16 minute read

2 step of DFS, union find practice

128.Longest Consecutive Sequences

9 minute read

practice of disjoint set

785.Is Graph Bipartite

5 minute read

use DFS or BFS, check if a graph is bipartite or not.

1080.Insufficient Nodes in Root to Leaf Paths

5 minute read

Practice to use DFS

337.House Robber III

10 minute read

practice of DFS

1390.Four Divisors

8 minute read

practice of a mathmatical algorithms

114.Flatten Binary Tree to Linked List

3 minute read

practice of DFS

802.Find Eventual Safe States

8 minute read

practice of DFS, this is an application of detecting cycle.

399.Evalutate Division

15 minute read

make use of graph, and disjoint set to find division rate

979.Distribute Coins in Binary Tree

4 minute read

practice to DFS

Detect Cycle in an Undirected Graph

3 minute read

using disjoint set, easily check if a graph has any cycle.

1302.Deepest Leaves Sum

3 minute read

practice to DFS

105.Construct Binary Tree from Preorder and Inorder Traversal

6 minute read

practice of binary tree traversal

How to implement and visualize Binary Tree

7 minute read

tips for making use of binary tree

959.Regions Cut By Slash

16 minute read

disjoint set, or union find algorithm is utilized.

947.Most Stones Removed with Same Row or Column

23 minute read

union find, disjoint set, dfs are used to solve this problem

How to implement Disjointset or Union Find using python

22 minute read

Let’s learn about disjiont set using python.

315.Count Smaller Numbers After Self

23 minute read

segment Tree, merge sort are utilized.

677.MapSumPairs

3 minute read

Trie datastructure practice

241.Different Ways to Add Parentheses - leetcode

5 minute read

Practice to utilize divide and conquer technique.

676.Magic Dictionary

13 minute read

Trie data structure practice

211.Add and Search Word - Leetcode

17 minute read

Trie datastructure practice.

how to find path on road network

41 minute read

we use dfs and dijkstra and a star algorithm to find ways

1023.Camelcase Matching Leetcode using python

10 minute read

Trie datastructure practice

How to implement Trie and Practice using python

65 minute read

Let’s learn about what is Trie and how to implement.

How to implement SegmentTree and Practice using python

42 minute read

Let’s learn about what is segment tree and how to implement.

Find Maximum Subarray Analysis comparing several algorithms using python

22 minute read

algorithm pratice to find maximum subarray problem.

N-Queens Problem using python

14 minute read

Good Pratice of DFS on 2D grid space.

DFS and BFS

17 minute read

Depth First Search and Bread First Search

973.K Closest Points - Leetcode

9 minute read

Find top K cloest points with origin.

932.Beautiful Array - Leetcode

10 minute read

using divide and conquer, find any beautiful array.

650.2 Keys Keyboard - Leetcode

8 minute read

Find the number of operations to make target string given 2 keys.

417.Pacific Atlantic Water Flow

15 minute read

Check if there are ways to go both Pacific, Atlantic ocean

169.Majority Element - Leetcode

6 minute read

Find Majority Elment in a given array

329.Longest Increasing Path - Leetcode

7 minute read

#

72.Edit Distance using python - Leetcode

10 minute read

#

932.Beautiful Array - Leetcode

10 minute read

permutate an array to become beautiful array using python

Detect Cycle using topolgoical sort python implementation

18 minute read

detect cycle in a given graph

Course Schedule - leetcode 207 and 210 using python

11 minute read

KEY: using BFS or DFS, detect cycles in a graph

721.Account and Merge

22 minute read

merge emails by finding same account from given input.

851.Loud and Rich using python - Leetcode

17 minute read

find a person who have the least quiet among people who have same, or more money

Binary Search using python

6 minute read

implement binary search recursive and iterative.

Pumping Oil using python

13 minute read

14.LCP using python - Leetcode

17 minute read

find longest common prefix among given words

935.Knight Dialer using python - Leetcode

18 minute read

find distinct ways to press dial pads

Karatsuba Algorithm for Binary Multiplication using python - Divide and Conquer

22 minute read

given two binary values, multiply efficiently.

Frevialds Algorithms for checking Matrix Multiplication randomly

22 minute read

How to check multiplication of given two square matrices.

Append and Delete - hackerrank

3 minute read

make source string to target string using Append and Delete operations

Rod Cutting Problem - Dynamic Programming

20 minute read

Rod Cutting Problem

Climing the Leaderboard - hackerrank

21 minute read

find ordered statstics from a user’s scores

9480.민정이와 광직이의 알파벳 공부

40 minute read

enumerate all cases, Target Sum

Counting Inversions using Divide and Conquer

18 minute read

algorithm practice, count inversions in a given array.

2D Cloest Pair python (Divide and Conquer)

43 minute read

using Divide and Conquer, solve 2D cloest pair problem

Quicksort with median of medians algorithm(efficient sorting)

32 minute read

Let’s learning about an algorithm that finds k-th elemen using median of medians to ensure linear time. And use it to quick sort algorithm.

735.Asteroid Collision

13 minute read

stack practice - how to use stack and how to think the use.

948.Bag Of Tokens

17 minute read

solve this problem using python and c++

129.Sum Root to Leaf Numbers

9 minute read

Find the total sum of all root-to-leaf numbers.

934.Shortest Bridge

13 minute read

Find shortest bridge between two islands

695.Max Area of Island

9 minute read

Given many islands, we want to find maximum size of island.

714.Stock Problem

13 minute read

sell stock with transaction fee

55.Jump Game

11 minute read

Determine if you are able to reach the last index.

Maximum Subarray Problem

8 minute read

Maximum Subarray Problem step by step

APM part2

65 minute read

Advanced Programming Methologies part2

APM part1

142 minute read

Advanced Programming Methologies part1

494.Target Sum

15 minute read

algoritm practice

Reeds-Shepp (RS) Path

19 minute read

이동체의 운동 구속조건을 반영하면 전진과 후진 경로에 대한 48가지 경로의 조합을 체크하는 RS path를 배워보자.

Model Predictive Control (MPC)

46 minute read

motion model로 다음 상태를 예측하여 비용함수를 만들고 모델을 제약사항으로 최적화를 하여 제어값을 찾아내는 MPC에 대해서 배워보자

RRT star

16 minute read

RRT star 알고리즘에 대해서 알아보자.

RRT

10 minute read

rrt 알고리즘에 대해 알아보고 코딩과 결과를 보자.

Random Walk Tutorial

7 minute read

random walk를 간단한 코딩을 통해서 배워보자

MCTS for Autonomous Driving

55 minute read

study

MCTS 튜토리얼 with TicTaeToe Example

49 minute read

Hidden Markov Model Theory

29 minute read

How HMM works and What is the theroy?

Implementation Gaussian HMM for Autonomous Driving

14 minute read

Run Gaussian HMM for continuous observation like Autonomous Driving

Implemetation of HMM

68 minute read

run hmm

Implementation of GMM-HMM

91 minute read

Run GMM-HMM

Implementation of Gaussian HMM

11 minute read

Run Gaussian HMM with hmmlearn

Rejection Sampling

10 minute read

Rejection Sampling 공부

Ristricted Boltzmann Machine

74 minute read

RBM 공부

MCMC and Gibbs Sampling

41 minute read

MCMC와 Gibbs Sampling 공부

Importance Sampling

12 minute read

Importance Sampling 공부

QR Decomposition

18 minute read

백터공간의 정규 직교 기저를 만드는 방법으로 활용되는 QR 분해를 배워보자.

Newton Method

28 minute read

Newton raphson method 와 Gauss newton method의 차이를 알아보자.

Matrix Transformation

18 minute read

선형변환을 행렬변환으로 표현하는 방법을 알아보자.

LU Decomposition

31 minute read

연립 선형 방정식 문제를 효율적으로 풀 수 있다.

Interior Point Method

84 minute read

barrier method라고 불리는 방법 에 대해서 알아보자.

Duality

16 minute read

primial problem을 lagrange dual problem으로 바꿔서 푸는 방법을 알아보고 의미를 분석해보자.

Fuel Cost Optimization Problem

7 minute read

최적화를 통해서 system dynamics에서 연료 사용을 최소화 하는 입력을 찾는 문제를 풀어보자.

Activity level selection problem

14 minute read

장사를 할 때 물건을 파는 행동에 대한 수준을 최적화를 통해서 결정해보자.

logistic regression with binomial distribution

7 minute read

binomial 분포를 갖고있는 데이터 셋을 가지고 logistic model을 사용해서 density를 추정해보자

robust least square method

8 minute read

huber penalty funtion을 사용했을때 least squard method에 어떤 장점이 있는지 알아보자

GMM for EM-algorithm

45 minute read

unsupervised problem for EM algorithm, especially gaussian mixture model.

MAB sutton book review

29 minute read

MAB basics tutorial

Inequality Summary

16 minute read

Let’s learn about inequality bounds.

Glove 알고리즘 정리

16 minute read

Glove 알고리즘에 대해 정리해보자

Word2Vec 알고리즘 정리

26 minute read

Word2Vec에 대해 정리해보자

Unsupervised Clustering: K-means and K-medoids

54 minute read

Let’s learn about representative unsupervised clustering algorithms

Dimensionality Reduction PCA, SVD Implementation

73 minute read

Let’s study dimensionality reduction.

Conjugate Gradient on Python Implementation

37 minute read

Let’s lean about conjugate gradient algorithm

Linear and Non-Linear Least Squares Regression on Python

32 minute read

Let’s study about Least Square Regression

Gradient Descent Algorithm on Python and Visualization

35 minute read

Let’s study about gradient descent algorithm

Newton Rapshon(or Gauss-Newton) Method with Implementation on Python

55 minute read

Let’s study about optimization newton raphson method

Transformer, Multi-head Attetnion Pytorch Guide Focusing on Masking

80 minute read

how to use transformer pytorch module with masking details

LEARNING ROBUST REWARDS WITH ADVERSARIAL INVERSE REINFORCEMENT LEARNING

50 minute read

dynamics에 robust한 reward function을 복원할 수 있는 방법을 제시

Memory Based Collaborative Filtering (User-User and Item-Item)

67 minute read

Let’s study about memory based collaborative filtering for recommender system

Content-Based(CB) Filtering

51 minute read

Let’s study about CB and implement it

Pandas DataFrame to MySQL

15 minute read

using MySQL and pymysql, data preprocessing can be easily possible.

Rewriting History with Inverse RL 리뷰

46 minute read

Hindsight Inference for Policy Improvement

Q-prop 논문 리뷰

24 minute read

Q prop 논문을 읽고 정리해보자

Attention Mechanism Summary

23 minute read

Attention Mechanism Categorized

Graph search의 응용

29 minute read

BFS와 DFS를 사용해서 무한히 큰 tree를 search해보자

Review of Regular expression and Automata Theory

less than 1 minute read

Let’s study about how to convert Rugular expression to Automata.

point cloud의 좌표계 변환 방법

28 minute read

point cloud 같은 수많은 좌표점들을 한번에 transformation matrix를 사용하여 원하는 위치와 위상으로 변환하는 방법을 알아보자

Dubin’s Path

104 minute read

Dubin’s path는 자동차의 운동역학을 고려한 경로를 생성하는데 사용된다. 단점은 후진을 모델링하지 않았다는 점이다. 이경로를 생성하는 방법을 알아보자

Implementation of Transformer - Tensorflow Tutorial Practice

123 minute read

Practice to Official Tutorial of Transformer

beta 분포의분석

43 minute read

beta 의 kl divergence와 loglikelihood계산과 분석

Random Variables

22 minute read

여러가지 랜덤변수들에 대한 의미와 분포, 각 변수들끼리의 관계에 기반한 평균, 분산의 의미들을 분석해보겠다.

Dynamic reconfiguration in ROS

9 minute read

ros 에서 rqt를 이용하여 interactive하게 paramter를 setting할 수 있는 방법을 알아보자

파일 관리와 관련된 리눅스 명령어

2 minute read

learn about linux command for file management

How to use GUI on Docker

6 minute read

Let’s learn about how to use GUI on docker

Git Collboartion

4 minute read

How to collaborate with others on git

Transformer, Multi-head Attetnion Pytorch Guide Focusing on Masking

80 minute read

how to use transformer pytorch module with masking details

Pandas DataFrame to MySQL

15 minute read

using MySQL and pymysql, data preprocessing can be easily possible.

Pack, Pad Sequence technique in pytorch

15 minute read

Pack padded sequence or pad packed sequence.

Pandas simple tutorial

20 minute read

pandas and mysql tutorial

How to use pymysql and mysql

15 minute read

A simple tutorial of pymysql and mysql.

How to implement progressive bar on python fantastically

6 minute read

simple tutorial of implement progressive bar on python

How to use argparse and yaml module on jupyter at the same time

5 minute read

simple tutorial of argparse and yaml

How to install horovod

3 minute read

horovod 모듈을 어떻게 설치하는지 알아보자

How to use git

29 minute read

git 사용법을 예제를 통해 베워보자

Tips For bash on Ubuntu

2 minute read

some command and explanations

How to use BERT in pytorch?

32 minute read

inspect BERT embedding and how to use BERT

How to install Eclipse CDT on Ubuntu 16.04

5 minute read

우분투에서 Eclipse CDT 설치 방법 가이드

Unable to display frame variables in Pycharm

less than 1 minute read

Collecting data… in pycharm

The Difference between Tensorflow and Pytorch using Embedding

45 minute read

Compare Tensorflow and Pytorch when using Embedding.

logging time using decorator in python

1 minute read

this post describes how to use decorator for logging time in python

Linux tips

9 minute read

Linux 를 다루는데 필요한 tip

Jupyter setup

9 minute read

setup tips for jupyter

byobu setup

2 minute read

tips for byobu

Window Anaconda setup

5 minute read

describe how to use anaconda on window

SSH tips

6 minute read

help ssh settings

Git tips

6 minute read

how to use git

GPU setup

16 minute read

setting for GPU

EAIRL

46 minute read

EAIRL 읽어보자

Glove 알고리즘 정리

16 minute read

Glove 알고리즘에 대해 정리해보자

Connection Between GAN, IRL and EBM

32 minute read

GAN과 EBM과의 연결성

TRPO 코드분석

19 minute read

TRPO 논문 구현 수식에 따른 코드를 읽어보자

Dattn [RecSys’17 review]

19 minute read

Dattn paper review

DQN 코드분석

12 minute read

DQN의 핵심 코드를 분석해보자

Transformer

56 minute read

global dependency를 잡아내고 횡방향으로 병렬 연산을 가능하게 하여 학습속도를 높인 RNN을 대체 가능한 attention model

Relay Policy Learning

27 minute read

multi-stage, long-horizon robotic tasks 를 해결하기 위한 Relay policy Learning (RPL) 방법

DAML [KDD’19] review

30 minute read

dual attention mutual learning KDD 2019 review

제주도 여행 조사

5 minute read

제주도 여행을 위한 조사

Start github.io Blog service

less than 1 minute read

I decided to start Github Blog service ‘github.io’ today

Pybullet Tutorial을 해보자.

41 minute read

pybullet의 기본 사용방법에 대해서 알아보자.

mujoco 설치방법

2 minute read

mujoco 라이센스 취득및 설치방법 그리고 gym custom environment를 setting하는 방법을 알아보자

How to deepcopy

13 minute read

how to deepcopy in python