• 로봇학회논문지
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• 제17권3호
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• pp.245-254
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• 2022

Sensor dataset for autonomous driving is one of the essential components as the deep learning approaches are widely used. However, most driving datasets are focused on typical environments such as sunny or cloudy. In addition, most datasets deal with color images and lidar. In this paper, we propose a driving dataset with multi-spectral images and lidar in adverse weather conditions such as snowy, rainy, smoky, and dusty. The proposed data acquisition system has 4 types of cameras (color, near-infrared, shortwave, thermal), 1 lidar, 2 radars, and a navigation sensor. Our dataset is the first dataset that handles multi-spectral cameras in adverse weather conditions. The Proposed dataset is annotated as 2D semantic labels, 3D semantic labels, and 2D/3D bounding boxes. Many tasks are available on our dataset, for example, object detection and driveable region detection. We also present some experimental results on the adverse weather dataset.

• Journal of Advanced Research in Ocean Engineering
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• 제4권2호
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• pp.53-65
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• 2018

The load condition significantly influences ship maneuverability in calm water. In this research, the effect of the load condition on turning performance of a very large crude oil carrier (VLCC) sailing in adverse weather conditions is investigated by an MMG-based maneuvering simulation method. The relative drift direction of the ship in turning to the wave direction is $20^{\circ}-30^{\circ}$ in ballast load condition (NB) and full load condition (DF) with a rudder angle $35^{\circ}$ and almost constant for any wind (wave) directions. The drifting displacement in turning under NB becomes larger than that under DF at the same environmental condition. Advance $A_d$ and tactical diameter $D_t$ become significantly small with an increasing Beaufort scale in head wind and waves when approaching, although $A_d$ and $D_t$ are almost constant in following wind and waves. In beam wind and waves, the tendency depends on the plus and minus of the rudder angle.

• 한국ITS학회 논문지
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• 제15권6호
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• pp.138-149
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• 2016

본 연구는 가상주행 시뮬레이터 실험을 통해 악천후시 가변 제한속도 표출 효과를 검토하였다. 본 연구는 기상변화 없이 제한속도를 낮추어 표출한 경우와 기상이 변화되었는데도 제한속도를 낮추어 표출하지 못한 경우는 운전자의 기대심리를 위배한 것으로 기상 변화에 따라 속도를 감속 표출하는 것에 비해 상대적으로 안전 측면에서 바람직하지 못하다고 가정하고 이를 가상주행 시뮬레이터 결과를 통해 검토하였다. 본 연구는 운전자의 기대심리에 부합되는 정도를 나타내는 지표로 운전자 순응도를 선택하였고, 이를 정량화하기 위한 수단으로 표출 제한속도를 포함한 일정 속도구간 내 누적확률밀도를 이용하였다. 검토결과, 운전자의 기대심리를 위배하였다고 가정한 조건들이 비교그룹에 비해 상대적으로 운전자의 주행행태적 측면에서 부정적인 것으로 평가되었다.

• 한국농공학회지
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• 제39권6호
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• pp.31-40
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• 1997

Potential impacts for unfavourable weather conditions and the assessment of the magnitudes of their adverse effects on crop yields were studied. EPIC model was investigated for its capability on crop yield predictions for rice and soybean. Weather generationmodel was used to generate long-term climatic data. The model was verified with ohserved climate data of Suwon city. Fifty years weather data including abnormal conditions were generated and used for crop yield simulation by EPIC model. Crop yield probability function was derived from simulated crop yield data, which followed normal distribution. Probable crop yield reductions due to abnormal weather conditions were also analyzed.

• 대한토목학회논문집
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• 제32권1D호
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• pp.23-31
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• 2012

부산광역시는 2007년부터 시내버스 준공영제를 시행하고 있으며 급격히 증가하고 있는 재정지원금이 큰 문제로 대두되었다. 현재 부산시의 재정 상태를 감안한 경우 시내버스 준공영제의 성공 여부는 매년 투입되어야 하는 재정지원금을 연차적으로 감소시켜 나가야 하는 부분이다. 부산시 재정부담을 완화하기 위해서는 시내버스 이용을 보다 편리하게 하여 버스 이용객의 수요를 지속적으로 증가시켜야 할 것이다. 교통수요에 영향을 미치는 기상조건을 살펴보면 눈, 안개, 비 등이 있으며 이러한 기상조건은 통행자들의 수단선택에 영향을 미쳐 결과적으로 버스 이용의 감소를 가져온다. 그리하여 기상 악화시 이용률 저하는 수익금 감소로 이어지게 되어 부산시의 막대한 공공재정 부담으로 돌아오게 된다. 본 연구에서는 기상 상태에 따른 교통수단간 수송 분담률을 파악하여 기상 악화시 버스 승객이 타 교통수단으로 전환하는 패턴을 분석하고 설문조사를 통해 타 수단으로 전환하는 이유를 분석함으로써 향후 대중교통시설 및 환승체계 구축 등 버스정책 수립에 필요한 정책적 시사점을 도출하는데 목적이 있다.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2024년도 춘계학술발표대회
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• pp.794-797
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• 2024

Despite advancements in deep learning, existing semantic segmentation models exhibit suboptimal performance under adverse weather conditions, such as fog or rain, whereas they perform well in clear weather conditions. To address this issue, much of the research has focused on making image or feature-level representations weather-independent. However, disentangling the style and content of images remains a challenge. In this work, we propose a novel fine-tuning method, 'freeze-n-update.' We identify a subset of model parameters that are weather-independent and demonstrate that by freezing these parameters and fine-tuning others, segmentation performance can be significantly improved. Experiments on a test dataset confirm both the effectiveness and practicality of our approach.

• 한국도로학회논문집
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• 제14권4호
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• pp.93-101
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• 2012

PURPOSES : Adverse weather conditions such as heavy rain, heavy snowfall, and thick fog and so on have highly affect on the change in traffic conditions on the road. In particular, heavy snowfall causes capacity reduction as well as crash occurrence. This study investigated the effects of snowfall on speed on a freeway. METHODS : Vehicle detection systems data were matched with corresponding weather station data by regression analysis. RESULTS : The results show that the travel speed is reduced by 6.7% under little snowfall and by 12.8% under heavy snowfall. Regarding the speed variation, 8.7% and 114.7% increases are observed under little snowfall and heavy snowfall, respectively. It is also found that 1 cm increase in snowfall leads to 0.4% decrease in travel speed. In addition, the travel speed increases by 0.4% when the temperature increases by $1^{\circ}C$. CONCLUSIONS : It is expected that the outcome of this study will be useful in establishing more effective strategies for winter operations and road maintenance in practice.

• 한국항공운항학회지
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• 제18권4호
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• pp.73-79
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• 2010

Flight test is the final and a mandatory process for the development of unmanned aerial vehicles(UAVs) as well as manned. Since most UAVs fly in a low speed and are prone to adverse weather conditions such as air turbulence, atmospheric weather environment around flight test regions will be a critical item to be considered for a flight test planning for UAVs. In this paper, we suggest a decision method for a UAV flight test schedule based on weather conditions of surface and upper atmospheres and also introduce a program for an effective flight test planning through weather forecasts.

• 대한조선학회논문집
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• 제56권6호
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• pp.497-506
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• 2019

Literature survey was conducted on the 2013 Interim Guidelines for determining the minimum propulsion power to maintain the manoeuvrability of ships in adverse conditions. The International Maritime Organization (IMO) Marine Environment Protection Committee (MEPC) documents related with the Guidelines were reviewed. Compatibility of the present Guidelines can be checked by two different levels: (Level 1) minimum power lines assessment and (Level 2) simplified assessment. The IHS (Information Handling Services) sea-web data on the bulk carriers and the tankers, which were built after 2000, were used to examine the Level 1 assessment. KVLCC2 was used to examine the Level 2 assessment. Regarding the Level 2 assessment, effects of the adverse weather conditions, the added resistance due to waves, the wake fractions and the thrust deduction factors were discussed.

• 해양환경안전학회지
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• 제23권3호
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• pp.250-257
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• 2017

This paper investigates minimum safe distances relative to a ship's four cardinal sides, as perceived by Filipino navigators when encountering dangerous elements and in adverse weather conditions when maneuvering in and around harbors. It uses a descriptive research method in the form of a questionnaire survey for experienced Filipino navigators of various ranks. During the course of research, 71 responses were colleted and the resulting data is presented in graphical and tabulated forms. Statistical methods including Pearson-product moment correlations, Cronbach's Alpha and ANOVA were used to identify internal associations, consistencies and significances, respectively. It has been proven that there are no significant differences in minimum safe distances relative to a ship's four cardinal sides, whether maneuvering while approaching a port or within an inner harbor. This study has been deemed significant for training future navigators, managing traffic in fairways, and designing harbors and maneuvering areas in the approaches to ports, among other applications. This work can also be used as a preliminary study for comparison with the well known safe domains presently in use.