of actual and suspicious black-ice cases that occurred during the last 10 years in the Republic of Korea. METHODS : Based on literature review, meteorological observation data associated with black-ice formation are selected: wind speed, air temperature (T), dew point temperature (Td), and relative humidity, to set minimum or maximum threshold values based on the normal distribution of each variable. In addition, weights are assigned based on the relationship among the variables to calculate the probability of occurrence. RESULTS : The threshold values are calculated using the average and standard deviation, resulting in 7.65 °C, 56.63%, 2.99 ms-1 for T-Td, relative humidity, and wind speed, respectively. Whereas the threshold value of T-Td and wind speed is set to the maximum threshold, that of the relative humidity is set to the minimum threshold value. These threshold values are applied to the diagnosis algorithm of black-ice formation, including a 1-h accumulated precipitation. CONCLUSIONS : The algorithm is expected to be utilized as a research methodology for diagnosing suspected cases of black ice.

ABSTRACT
1. 서론
2. 연구방법
    2.1. 선행연구 조사 및 활용
    2.2. 블랙아이스 실제 및 의심 사례 자료 수집
    2.3. 블랙아이스 기상요소 임계기준 설정
3. 블랙아이스 진단 알고리즘 로직 개발
4. 결과 및 고찰
REFERENCES

• 김완희(㈜웨더피아 대리) | Kim, Wanhee
• 강서영(㈜웨더피아 차장) | Kang, Seoyoung
• 박소연(㈜웨더피아 연구원) | Park, Soyeon
• 임상욱(㈜웨더피아 대표) | Lim, Sangwook Corresponding author