Introduction

These are the collections of research projects and software portfolios that are categorized based on the topics relevant in the field of artificial intelligence and machine learning. Also included are coding exercises that demonstrates algorithmic problem solving skills.

Table of Contents

• About Me
• Mostly Used Languages
• AI/ML Research Projects
  • Extrapolative behavior of ML models
    • The project demonstrates comparative difference of extrapolative behavior between various ML models and reports quantitative/qualitative measures of performance against that of human on simple non-linear simulation datasets.
    • 
  • Automated end-to-end causal inference application
    • The project aims to bring exploratory data analytics and causal inference to generic users who are not familiar with data science particularly with the concept of in-dept machine learning models and intricacy of causal inference.
    • 
  • Human extrapolative behavioral experiment via web application
    • The human part of the extrapolation project to take comparative measures on investigating human like behaviors from various ML algorithms such as random forest and deep neural networks. In order to deliver the behavioral experiments to 150 participants recruited on AWS, the web app was created and hosted on heroku.
    • 
  • Probabilistic linkage of real-world clinical data
    • In order to link multiple datasets acquired from different sections of the JHU medicine network, this data management pipeline was built in support of collective mission of CDEM. The pipeline uses fastlink R package to automate probablistic linkage of multiple datasets which bases on expectation-maximaztion algorithm.
    • 
  • Multivariate time-series hologram biometric signal parsing
    • The real-world data most often involves significant noise that perturbs extraction of the signal of interest. This project aims to parse out biometric signals from multivaraite time-series hologram data where EEG read out coninsides with other physiological responses such as heart beat.
    • 
• Coding
  • Algorithm & Data Structure
  • Sorting
  • SQL
  • Bash & Shell

About Me

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Mostly Used Languages

AI/ML Research Projects

The projects that involve machine learning and artificial intelligence are listed here.

1. Extrapolative behavior of ML models



Github Repo: https://github.com/jshinm/inductive-bias-experiment

One of the purposes of machine learning models is a prediction of trend based on the patterns of given data. The issue is that these ML models are interpolative by nature and does not perform well as extrapolators. Despite that, ML models are widely used for forecasting uncharted territory. This project tests examines extrapolative behaviors of the ML algorithms such as random forest, neural networks, support vector machines and measure performance against humans.



These ML algorithms are trained on non-linear simulation datasets (gaussian XOR shown above) and their posterior probability distributions are drawn out in a form of a grid for comparison. The line plot is indicative of increasing Hellinger distance for neural nets posteriors more so than both random forest and humans as we move further away from the origin, which suggests that the latter algorithm is more similar to the former algorithm in this experiment.



As these non-linear datasets are not space-invariant, we can assess the posterior in a piece-wise manner. The linear evaluation with a function of angle reveals more drastic difference between neural nets and random forest where the former algorithm reaches the limit of posterior much faster than that of the latter indicating that neural nets is not only misrepresentative of spiral simulation estimation but it is also more confident in its decision.

2. Automated end-to-end causal inference application

Github Repo: --

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3. Human extrapolative behavioral experiment via web application

Github Repo: https://github.com/jshinm/deepnet-behavioral

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4. Probabilistic linkage of real-world clinical data

Github Repo: https://github.com/jshinm/probabilistic-linkage

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5. Multivariate time-series hologram biometric signal parsing

Github Repo: https://github.com/jshinm/hologram-biometric-signal-parsing

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Software Development

Current and past software projects.

Project	Description	Code
WebApp for machine versus human extrapolation experiment	Desc1	Code1
Web Scrapper for data mining on GitHub repository	Desc2	Code2
P&L generator for tax report	Desc2	Code2
Pandarize	Desc2	Code2
Amortized loan simulator	Desc2	Code2
Omega Messenger	Desc2	Code2
FlipScope	Desc2	Code2
KeeWee	Desc2	Code2

Kaggle Projects

Some data science side projects for Kaggle challenges

Project	Code
Item1	Code1
Item2	Code2

Coding

The following is the programming exercise that covers various algorithms and data structures. There is a dedicated section for sorting. Also contains is sql and bash/shell coding challenges.

Algorithm & Data Structure

Problem Name	Platform	Note
Two Sum	LeetCode	Blind 75 Qs
Two Sum II - Input Array Is Sorted	LeetCode
Two Sum IV - Input is a BST	LeetCode
Reverse Integer	LeetCode
Palindrome Number	LeetCode
Roman to Integer	LeetCode
Longest Common Prefix	LeetCode
Longest Substring Without Repeating Characters	LeetCode	Blind 75 Qs
Container With Most Water	LeetCode	Blind 75 Qs
Three Sum	LeetCode	Blind 75 Qs
Remove Nth Node From End of List	LeetCode	Blind 75 Qs
Valid Parentheses	LeetCode	Blind 75 Qs
Merge Two Sorted Lists	LeetCode	Blind 75 Qs
Merge k Sorted Lists	LeetCode	Blind 75 Qs, only TLE Solution
Combination Sum	LeetCode	Blind 75 Qs
Search in Rotated Sorted Array	LeetCode	Blind 75 Qs
Group Anagrams	LeetCode	Blind 75 Qs
Rotate Image	LeetCode	Blind 75 Qs
Maximum Subarray	LeetCode	Blind 75 Qs
Climbing Stairs	LeetCode	Blind 75 Qs
Spiral Matrix	LeetCode	Blind 75 Qs
Jump Game	LeetCode	Blind 75 Qs
Merge Intervals	LeetCode	Blind 75 Qs
Insert Interval	LeetCode	Blind 75 Qs
Unique Paths	LeetCode	Blind 75 Qs, only TLE Solution
Sort Characters By Frequency	LeetCode
Set Matrix Zeroes	LeetCode	Blind 75 Qs
Minimum Window Substring	LeetCode	Blind 75 Qs
Word Search	LeetCode	Blind 75 Qs
Decode Ways	LeetCode	Blind 75 Qs
BinaryGap	Codility
CyclicRotation	Codility
OddOccurrencesInArray	Codility
FrogJmp	Codility
PermMissingElem	Codility
TapeEquilibrium	Codility
FrogRiverOne	Codility
PermCheck	Codility
MaxCounters	Codility
MissingInteger	Codility
PassingCars	Codility
CountDiv	Codility
GenomicRangeQuery	Codility
MinAvgTwoSlice	Codility	50% Solution
Distinct	Codility
MaxProductOfThree	Codility
Triangle	Codility
NumberOfDiscIntersections	Codility
Brackets	Codility
Fish	Codility	87% Solution
Nesting	Codility
StoneWall	Codility	92% Solution
Dominator	Codility
EquiLeader	Codility	33% Solution
MaxProfit	Codility
MaxSliceSum	Codility
MaxDoubleSliceSum	Codility
CountFactors	Codility

Data Structure Examples

Name	Example
Heap	Note

Sorting (simulation notebook)

Name	Best TC	Average TC	Worst TC	Worst SC	Stability
Bubble Sort	Ω(N)	Θ(N^2)	O(N^2)	O(1)	Stable
Selection Sort	Ω(N^2)	Θ(N^2)	O(N^2)	O(1)
Insertion Sort	Ω(N)	Θ(N^2)	O(N^2)	O(1)	Stable
Shell Sort	Ω(N log N)	Θ(N log^2 N)	O(N log^2 N)	O(1)
Heap Sort	Ω(N log N)	Θ(N log N)	O(N log N)	O(1)
Merge Sort	Ω(N log N)	Θ(N log N)	O(N log N)	O(N)
Quick Sort	Ω(N log N)	Θ(N log N)	O(N^2)	O(logN)
Counting Sort	Ω(N+K)	Θ(N+K)	O(N+K)	O(K)
Tree Sort	Ω(N log N)	Θ(N log N)	O(N^2)	O(N)
Tim Sort	Ω(N)	Θ(N log N)	O(N log N)	O(N)
Smooth Sort	Ω(N)	Θ(N log N)	O(N log N)	O(1)
Radix Sort	Ω(NK)	Θ(NK)	O(NK)	O(N+K)

Database [SQL (syntax note) || Python]

Problem Name	Platform	Language
Combine Two Tables	LeetCode	SQL
Second Highest Salary	LeetCode	SQL
Nth Highest Salary	LeetCode	SQL
Rank Scores	LeetCode	SQL
Consecutive Numbers	LeetCode	SQL
Employees Earning More Than Their Managers	LeetCode	SQL
Duplicate Emails	LeetCode	SQL
Customers Who Never Order	LeetCode	SQL
Department Highest Salary	LeetCode	SQL
Department Top Three Salaries	LeetCode	SQL
Delete Duplicate Emails	LeetCode	SQL
Rising Temperature	LeetCode	SQL
Trips and Users	LeetCode	SQL
Big Countries	LeetCode	SQL
Classes More Than 5 Students	LeetCode	SQL
Human Traffic of Stadium	LeetCode	SQL
Not Boring Movies	LeetCode	SQL
Exchange Seats	LeetCode	SQL
Swap Salary	LeetCode	SQL
Reformat Department Table	LeetCode	SQL
SqlEventsDelta	Codility	SQL
SqlWorldCup	Codility	SQL
Weather Observation	HackerRank	SQL
SQL Project Planning	HackerRank	SQL
Interviews	HackerRank	SQL
15 Days of SQL	HackerRank	SQL
Japanese Population	HackerRank	SQL
Aggregation	HackerRank	SQL
Acceptance Rate By Date	StrataStratch	Python
Highest Energy Consumption	StrataStratch	Python
Finding User Purchases	StrataStratch	Python
Popularity Percentage	StrataStratch	Python
Highest Cost Orders	StrataStratch	Python
Users By Avg Session time	StrataStratch	Python
Top 5 States With 5 Star Businesses	StrataStratch	Python
Finding Updated Records	StrataStratch	Python
Risky Projects	StrataStratch	Python
Number Of Bathrooms And Bedrooms	StrataStratch	Python
Customer Details	StrataStratch	Python
SMS Confirmations From Users	StrataStratch	Python
Customer Revenue In March	StrataStratch	Python
Find the rate of processed tickets for each type	StrataStratch	Python
Find the overall friend acceptance count for a given date	StrataStratch	Python
Daily Interactions By Users Count	StrataStratch	Python
Successfully Sent Messages	StrataStratch	Python
Popularity of Hack	StrataStratch	Python
Most Active Users On Messenger	StrataStratch	Python
Average Salaries	StrataStratch	Python
Spam Posts	StrataStratch	Python
Total Cost Of Orders	StrataStratch	Python
Classify Business Type	StrataStratch	Python
Top Cool Votes	StrataStratch	Python
Order Details	StrataStratch	Python
Workers With The Highest Salaries	StrataStratch	Python, SQL
Reviews of Categories	StrataStratch	Python, SQL
Highest Salary in Department	StrataStratch	Python, SQL
Distances Traveled	StrataStratch	Python, SQL
Gender with Generous Reviews	StrataStratch	Python, SQL
Rank Variance Per Country	StrataStratch	SQL
Users By Average Session Time	StrataStratch	SQL
Finding User Purchases	StrataStratch	SQL
Highest Cost Orders	StrataStratch	SQL
Total Cost of Orders	StrataStratch	SQL
Ranking Most Active Guests	StrataStratch	SQL
Algorithm Performance	StrataStratch	SQL

Bash & Shell

Problem Name	Platform
Comparing Numbers	HackerRank
Comparing Strings	HackerRank
Loop and Skip	HackerRank
Arithmetic Operations	HackerRank
Compute Average	HackerRank
Cut Command	HackerRank
Text Processing	HackerRank