PURPOSES : The aim of this study is to develop a road fog information system based on the geostationary meteorological satellite (GK2A) for road weather services on highways. METHODS : Three threshold values sensitive to fog intensity in the GK2A fog algorithm were optimized using multi-class receiver operating characteristic analysis to produce road fog information depending on day and night. The developed a GK2A road fog algorithm that can detect three levels of road fog based on the visibility distance criteria (1km, 500m, and 200m). Furthermore, the GK2A road fog product was not only substituted with visibility objective analysis data in unknown and cloud-covered areas of satellite data, but also integrated with visibility distance data obtained from visibility gauges and CCTV image analysis to improve the accuracy of road fog information. RESULTS : The developed road fog algorithm based on meteorological satellite data provides real-time road fog information categorized into three levels (attention, caution, and danger) based on the visibility distance, with a spatial resolution of 1km × 1km and temporal resolution of 5 minutes. The road fog algorithm successfully detected road fog in five out of seven fog-related traffic accidents reported by Korean media outlets from 2020 to 2022, resulting in a detection success rate of 71.4%. The Korea Meteorological Administration is currently in the process of installing additional visibility gauges on 26 highways until 2025, and the next high-resolution meteorological satellite (GK5) is planned to be launched in 2031. We look forward to significantly improving the accuracy of the road fog hazard information service in the near future. CONCLUSIONS : The road fog information test service was initiated on the middle inner highway on July 27, 2023, and this service is accessible to all T-map and Kakao-map users through car navigation systems free of charge. After 2025, all drivers on the 26 Korean highways will have access to real-time road fog information services through their navigation systems.

This study evaluated the effectiveness of odor reduction when spraying inside the Bio-curtain (hereinafter referred to as curtain) according to the exhaust fan operating rate. Spraying is a main factor affecting the ability to odor reduction of curtains. The curtain (total area: 37.9m3) was constructed with two layers of light-shielding screens stretched over a rectangular parallelepiped structure installed around an exhaust fan (630 mm) on the side wall of a pig barn. Air samples for odor analysis were collected from inside the pig barn and outside the curtain. The main odorous compounds such as volatile fatty acids, phenols, indoles, and ammonia were measured. The odor reduction effectiveness was evaluated by total odor activity values (TOAVs) summed to the odor activity values of each odorous compounds. Depending on the exhaust fan operating rate, the reduced rate of TOAVs gradually decreased to the range between 15.67% and 68.80%. Because the contact time between the spraying liquid and the air velocity of the exhaust fan becomes shorter (or there is a reduction in liquid to gas flow ratio) as the exhaust fan operating rate increases. The results of this study can be used as basic data for research into spraying conditions to improve the odor reduction effectiveness of curtains.

PURPOSES : Demonstrated performance degradation of LiDAR for vehicle and pedestrian dummy in rainy and foggy road conditions. METHODS : In real-scale rain and fog road conditions, adjust the distance between LiDAR and the measurement target from 10m to 70m (in 10m interval), measure LiDAR NPC (number of point cloud) and intensity, and compare the resulting numerical values. RESULTS : LiDAR's NPC and Intensity showed statistically significant differences by overall weather condition (normal, rain, fog), and the values were found to be larger in the order of normal>rainfall>fog. In the case of vehicles, sunder rain conditions, NPC and intensity are recognized even at 70m as in normal conditions, but under fog conditions, NPC and intensity are measured only up to 30m. In the case of pedestrians, the reflective area size is smaller than that of vehicles, so they are recognized only up to 30m in rainy conditions, and NPC and intensity are measured only up to 20m in fog conditions. CONCLUSIONS : It was confirmed that LiDAR performance deteriorates in rain and fog compared to normal.

PURPOSES : LED based Variable Message Signs(VMS) have been widely used to inform safety messages to the drivers in advance. Legibility Distance of VMS is the most important factor to provide the safety messages to drivers in timely and effective way. However, current National Standards on legibility distance design considers letter size only even there is a difficulty to read the signs at adverse weather conditions such as heavy fog. So, this study examined the legibility issue under fog by evaluating the legibility distance with two design factors such as letter size and luminance. METHODS : Two foggy weather conditions, intermediate and heavy fog, were simulated at real-road-scale Proving Ground. Legibility distance at daytime and nighttime was evaluated by test subjects. Subjects were asked to fill the legible distance on the test sheet and statistical significant was analysed at the lab. RESULTS : The legibility distance(LD) under fog was observed only 22 to 41% of LD observed under normal weather condition at daytime, and 26 to 45% at nighttime condition. Study results showed a consistent increase in LD with higher luminance even at same letter size and vice versa conditions, However, statically significant difference between groups was only revealed when both letter size and luminance level increased conditions. In order to apply the test results in terms of engineering benefits, LD results from significantly different groups was evaluated with relative to Stopping Sight Distance(SSD) within conceptual frame suggested in this study. CONCLUSIONS : From the study results, current National Standard on legibility distance design needs to consider letter size and luminance simultaneously to response the legibility issue in adverse weather conditions.

본 연구에서는 2 016년부터 2 02 0년까지 내륙 관측소 중 안개 최다발 지역인 안동을 대상으로 XGBoost-DART 머신러닝 알고리즘을 이용하여 1 시간 후 안개 유무를 예측하였다. 기상자료, 농업관측자료, 추가 파생자료와 각 자료 를 오버 샘플링한 확장자료, 총 6개의 데이터 세트를 사용하였다. 목측으로 획득한 기상현상번호와 시정계 관측으로 측 정된 시정거리 자료를 각각 안개 유[1]무[0]로 이진 범주화하였다. 총 12개의 머신러닝 모델링 실험을 설계하였고, 안개 가 사회와 지역사회에 미치는 유해성을 고려하여 모델의 성능은 재현율과 AUC-ROC를 중심으로 평가하였다. 전체적으 로, 오버샘플링한 기상자료와 기상현상번호 기반의 예측 목표를 조합한 실험이 최고 성능을 보였다. 이 연구 결과는 머 신러닝 알고리즘을 활용한 안개 예측에 있어서, 목측으로 획득한 기상현상번호의 중요성을 암시한다.

PURPOSES : In this study, a system is investigated and developed to remove fog by injecting air onto a road using high-pressure air generated by turbo blowers installed on both edges of the road without using artificial chemicals. METHODS : A test device was constructed on a scaled road measuring 5 m long. A 225 kW class turbo blower was used to supply air. An air injection nozzle was installed to allow high-pressure air supplied from the turbo blower to be sprayed vertically from the edge of the road and horizontally from the surface of the road. Ten micro humidifiers were used to generate fog. RESULTS : Experimental results show that when ground fog occurs on the road, spraying air only in the vertical direction cannot effectively remove the fog. However, when vertical and horizontal nozzles are used simultaneously, both ground fog and flowing fog are removed effectively. CONCLUSIONS : A system for removing fog by spraying air jet is constructed, and fog is generated using a micro humidifier. Results from the fog removal performance test show that the system effectively removes fog.

PURPOSES : This study aimed to examine the effect of fog on the optical properties of taillights and the relationship between luminous intensity and the visibility distance of taillights on the road. METHODS : Changes in luminous intensity were measured using a light meter. Participants subjectively evaluated visibility distance. The artificial fog was reproduced using weather-generating facilities at the Center of Road Weather Proving Ground (CRPG). RESULTS : As expected, the average luminous intensity under intermediate fog conditions was reduced to 72% compared to normal weather conditions and 44% under heavy fog conditions in the case of the tail lamp-only lit condition. In the case of the tail lamp and brake lamp lit condition, the average luminous intensity was reduced to 76% under heavy fog conditions and 55% under intermediate fog conditions compared to normal dry conditions. In addition, the average visibility distance was reduced by 41% when fog conditions changed from intermediate to heavy in the case of the tail lamp-only lit condition and 39% in the case of the tail lamp and brake lamp lit conditions. Changes in visibility distance corresponding to the gradual change in luminous change were evaluated by participants, and the linearly regressed equations for the relationship between the intensity levels and the visibility distance were derived and examined for their meaning in terms of road traffic safety concerning stopping sight distance. CONCLUSIONS : Luminous intensities were suggested, given the design speeds, to satisfy the minimum stopping distances. In addition, the required speed reduction allowances were suggested given the design speeds if the luminous intensity remains unchanged.

본 연구는 4대강사업으로 이미 조성된 팔당 물안개공원을 재생하기 위해 허브 주제원을 도입 하고 이를 구체화하기 위한 전략적 방안을 주로 물리적 측면에서 다룬 내용이다. 기존공원의 재활성화를 위한 전략으로 현 공간구조를 오방(五方)의 전통적 장소 맥락에서 재해석하였으며, 이에 기초하여 단위 공간별 주제를 조직화하고 허브 식재방식과 시설요소를 ‘두텁게 하는 전략’을 활용하였다. 또한, 새롭게 도입될 주제원을 위한 스토리텔링의 장치요소를 제안함으로써 이용자와 환경 간에 다양한 감성 교류와 공감 강화를 겨냥하였다. 한편 입지특성에 의해 오랫동안 공공복지 관련 개발행위조차도 제한되어 온 계획대상지 주변 상황을 고려하여, 수도권 수변 휴양공간의 확충과 함께 지역주민의 소득증대와 공공복지활동에 탄력적으로 대응하는 환경을 구축하도록 하였다. 계획수립에 따른 예상효과가 상부 기관으로부터 인정받아 해당 예산을 이미 확보한 본 사업은 2022년 준공을 목표로 하고 있는바, 본 사업의 충실한 질적 완성을 기대한다.

본 논문에서는 패치 반복을 이용하여 대기광 추정을 통해 개선된 안개 제거 방법을 제안한다. 기존의 안개 제거 방법은 영상 내에 인공적인 빛이나 밝은 물체가 있는 경우 대기광 추정 시 오차가 발생 한다. 이 방법은 안개 영상의 화소들 중 가장 밝은 값으로 대기광을 추정하기 때문이다. 이러한 문제를 해결하기 위하여, 제안하는 방법은 패치 쌍 사이의 안개 양의 차이점을 이용한다. 패치 쌍은 안개의 양이 다르지만 유사한 패턴을 가지고 있기 때문에, 대기광이 동일하다고 가정할 수 있다. 이러한 특성을 통해 각 패치 쌍으로 구한 대기광에 다른 가중치를 부여함으로써 대기광을 추정할 수 있다. 실험을 통해 제안하는 방법이 기존의 방법보다 안개 제거 성능에서 우수함을 확인하였다.

국산 안개초 ‘Dream Song’ 가을~초겨울 절화 재배시 개화 촉진 및 절화 생산성 향상에 적절한 광원 선발을 위해 전조 광원별 생육 및 개화특성을 조사하였다. 백열등의 광질은 청색, 적색 및 원적외선 파장 모두 높고 고압나트륨등(HPS)은 적색 파장이 약간 높았으며, LED는 청색이 적색 파장보다 높았고 삼파장등은 청색과 적색 파장이 낮게 조사되었다. 주간(13:00)과 야간(전조 1시간 후, 23시)에 측정한 엽록소 형광 반응은 광원별로 차이가 없었다. 백열등과 고압나트륨등이 생육 진전이 빨라 출뢰 및 개화가 촉진되었으며, 화경장과 절화장이 길고 분지수와 개화율이 높아 절화량도 많았다. LED 전조는 개화 촉진 효과는 적었으나 분지수가 향상되었다. 따라서 경영비를 고려한 국산 안개초 ‘Dream Song’ 전조 재배 시 광원은 백열등이 적정하다고 생각된다.

국내 육성 안개초 신품종 ‘Dream Song’과 ‘Pearl Stars’의 평 야지 농가 현장 보급 확대를 위한 가을∼초겨울 절화 생산작 형 개발을 목적으로 여름철 정식시기에 따른 개화시기 및 절 화 생산성을 조사하였다. 정식에서 개화까지의 소요일수는 두 품종 모두 6월 30일 정식이 다른 정식시기보다 짧았으며, ‘Pearl Stars’가 ‘Dream Song’보다 2∼6일 더 길었다. 화경장, 측지수, 분지수 및 줄기 굵기는 두 품종 모두 정식시기가 늦을 수록 증가하는 경향이었으며, 특히 화경장은 ‘Pearl Stars’가 ‘Dream Song’보다 더 길었다. ‘Dream Song’은 정식시기가 늦 을수록 절화장, 절화중이 증가하고 소화가 커졌으며 절화량도 증가하여 7월 15일 이후 정식에서 절화품질이 우수하고 생산 성이 향상되었다. ‘Pearl Stars’도 ‘Dream Song’과 마찬가지로 정식시기가 늦을수록 절화장이 길고 소화가 커졌으며 절화 생 산량은 증가하다가 7월 30일 정식에서 감소하였다. 따라서 ‘Dream Song’은 7월 15일부터 7월 30일 이내에 정식하여 10 월∼12월 상순 절화 생산에, ‘Pearl Stars’는 6월 30일부터 7월 15일 전후에 정식하여 9월∼11월 절화 생산 작형에 적합할 것 으로 생각된다.

본 연구에서는 구미에 위치한 낙동강에서 발생한 안개를 분류하였고 안개 발생 전후의 기상특성을 분석하였다. 안개는 2013년부터 2015년까지 시정계를 이용하여 관측되었다. 안개는 총 74회 발생하였고 대부분 증기안개로 분류되 었다. 관측된 증기 안개는 내륙에서 발생한 안개보다 지속시간이 길게 나타났는데 이는 지형적 특징으로 인해 야간 증 발이 다른 지역보다 강하게 나타났기 때문이다. 안개 지속시간에 대한 하천 증발 효과를 분석하기 위해 Penman- Monteith (Penman법)와 Bulk aerodynamic (Bulk법) 방법을 사용하여 증발량을 추정하였다. 이 중 Bulk법은 실제 수면 에서 측정한 증발량과 유사하게 나타났다. 따라서 Bulk법이 실제 수면 증발량 추정에 적합한 방법임을 확인할 수 있었 다. Bulk법으로 추정한 증발량은 안개 비발생일 보다 안개 발생일에 06 LST와 07 LST에 더 높게 나타났다. 안개 발 생일에 하천의 증발은 대기에 증발잠열 에너지를 공급하고 안개 내부의 난류를 유지하는 에너지원으로 작용한다. 이와 같은 결과는 안개내부의 풍속, 기온, 그리고 난류운동에너지의 증가를 통해 확인하였다.

본 논문에서는 선박의 안전운항을 위하여 안개 발생 시 엔진을 자동으로 제어하여 피해를 최소화하거나 회피할 수 있도록 자동 제어 시스템을 설계 및 제작 하였다. 제작된 동력 자동제어시스템은 ATmega128과 RPM감지회로를 사용하여 안개발생부에서 인위적으로 안개를 발생시켜 RPM의 변화량을 측정하였다. 이를 위하여 전체구성도를 작성하였으며 홀센서가 있는 모터를 사용하여 PWM 제어를 하 도록 ATmega128에 Source code를 적용시켰다. 추후, 제작된 동력 자동제어장치를 통하여 실제 선박에서의 실험 및 안전성평가를 마련할 계 획이다.

This study was investigated the effect of heating time (taken the pots transplanted perennial root in heating greenhouse from Dec. 30 to Mar. 2 as 10 days interval) after 1st cut-flower harvesting on the growth, flowering time, and cut-flower productivity of domestic bred Gypsophila paniculata ‘Dream Song’ in plain area. As the later heating time, the shorter days to shoot emergence and flower budding as the longer exposed to low temperature, and blooming was promoted with increasing the air temperature within greenhouse. Flower stalk length, node number, and stem diameter were inclined to decline in later heating time. In Dec. 30 heating time, node number on a main stem was many, but primary branches number was low due to insufficient breaking of dormancy. Cut flower length was not significantly different as affected by heating time, fresh weight got declined as the later heating time and then drastically decreased in Mar. 2. Cut-flower yield was not significantly different among heating time except for both Dec. 30 insufficiently exposed to low temperature and Mar. 2 shortened the growth duration caused by relatively high temperature. It was thought that the dormancy of ‘Dream Song’ broke after the middle of January under natural low temperature, and the production of second crop should be cultivated within Feb. 20 from mid January.

OBJECTIVES : A fog generated field test was conducted to analyze the relationship between different sizes of variable speed limit signs and the legibility distance under various fog density conditions. By using this study, appropriate sizes of signs can be selected depending on the density of fog. METHODS : An actual tunnel was selected as the area for this test, as other places cannot maintain the fog condition because of rapid air current. A total 121 subjects were recruited for this test, which took place over the course of four days. The test on the first day was conducted under normal weather conditions for comparison. Visibility-distance detecting sensor was used to measure the visibility distance due to the fog density time, simultaneously with the evaluation of legibility distance by subjects. RESULTS : The test results show the relationship between the different sizes of signs and the legibility distance corresponding to the visibility distance due to both non-fog and fog generated conditions. According to the technical test results, appreciable amount of reduction in legibility distance due to fog was resulted in all sizes of signs. Moreover, the legibility distance is reduced proportionately with the decrease in the visibility distance due to fog. CONCLUSIONS : The results of this study can be used to select appropriate sizes of valuable speed signs under fog conditions. Hence, drivers can expect to have more room to respond to adverse weather conditions, thereby reducing the risk of accidents.