Sangmin Lee

Arctic Route Accessibility Analysis

Question · How much has sea-ice loss changed the operational window of Arctic routes, and what choice does that leave a Korean shipper?

Decision value · Reduced the finding to two decision-grade numbers, navigable months per year and nautical miles saved, so routes can be compared on when and for how long they are usable.

Boundary · Navigable months describe physical accessibility under concentration thresholds; they do not mean commercial transit is operationally viable.

Busan Station Dwell Conversion Analysis

Question · What does a ridership-based policy target list miss? Are alighting and dwelling the same thing?

Decision value · Ranking stations by failed dwell conversion instead of raw ridership produces a different target list for commercial-district renewal budgets, and producing that list is the point of the analysis.

Boundary · Dwelling population and dwell time are estimated from gate records; they are not measured mobility data from telecom or card sources.

Telecom Customer Churn Analysis

Question · Which customers are most likely to leave, why are they at risk, and which retention response fits each segment?

Decision value · The analysis turns a binary prediction task into a prioritization framework and proposes retention strategies targeting a 5.0 percentage-point reduction in churn; the target has not been achieved or validated.

Boundary · The 5.0 percentage-point churn reduction is a proposed planning target, not an achieved business result.

Satellite Night-Light GDP Analysis

Question · Can night-light intensity help explain GDP where official statistics are limited, and do urban population and electricity access change that relationship?

Decision value · Night-light data can provide a complementary signal for early market screening, country-risk research, and economic monitoring where conventional reporting is limited.

Boundary · R-squared = 0.819 describes explanatory fit in the simple model; it is not 81.9% prediction accuracy.

Quant Trading Automation

Question · What does running trading rules as a service require beyond strategy code, and how do you confirm the rules actually have an edge?

Decision value · Instead of claiming returns, set out in numbers and operating controls the conditions under which a strategy may run and the signals that should switch it off.

Boundary · Paper-trading validation only. Backtest figures are simulations on historical data and claim no real-money operation, return, win rate, or capital growth.

Financial AI Model Study

Question · How do preprocessing, regularization, model complexity, and hyperparameters affect validation and test performance?

Decision value · Use additional complexity only when validation evidence justifies it; a more advanced method is not automatically the stronger business choice.

Phorage Brand and Commerce MVP

Question · How can a personal photography concept be translated into a testable product and service experience before public launch?

Decision value · The project demonstrates service planning, MVP prioritization, physical-digital integration, and the definition of launch hypotheses and metrics.

Boundary · Pre-launch MVP only. No public launch, public traction, large-scale orders, or verified sales metrics are claimed.

Blood Type and Personality Survey Study

Question · Does a familiar social belief about blood type and personality remain supported when translated into hypotheses and tested with survey data?

Decision value · The study demonstrates how to turn a popular claim into testable hypotheses and restrict the conclusion to what the evidence supports.

Boundary · One isolated significant result does not prove a broad relationship between blood type and personality.