Better understanding the mechanism of black ice occurrence on the road in winter is necessary to reduce the socio-economic damage it causes. In this study, intensive observations of road weather elements and surface information under the influence of synoptic high-pressure patterns (22nd December, 2020 and 29th January, and 25th February, 2021) were carried out using a mobile observation vehicle. We found that temperature and road surface temperature change is significantly influenced by observation time, altitude and structure of the road, surrounding terrain, and traffic volume, especially in tunnels and bridges. In addition, even if the spatial distribution of temperature and road surface temperature for the entire observation route is similar, there is a difference between air and road surface temperatures due to the influence of current weather conditions. The observed road temperature, air temperature and air pressure in Nongong Bridge were significantly different to other fixed road weather observation points.

This study aimed to classify typhoons using a more objective index based on strong winds and precipitation data from 1904 to 2019 obtained from the Automated Surface Observing System. The Typhoon Type Index (TTI) was calculated by classifying wind speed and precipitation of each typhoon, thereby revealing the rate and characteristics of the wind-type and rain-type typhoons. In addition, the top 10 typhoons for property damage were analyzed by dividing them into three types according to the typhoon course. The analysis showed that typhoons of type 1, heading north to the west coast, were most clearly affected by the wind. In addition, the impact of the wind was reduced and the impact of rain increased in the order of typhoon type 2 that landed on the southern coast and type 6 that affected the Korean Peninsula through China.

The purpose of this study was to analyze examples of green infrastructure presented by the American Society of Landscape Architects as a part of basic research to assess hub green spaces in cities. With the specific goal of green infrasturcture in mind, the study samples were classified according to their purpose: ‘humanities’, ‘hydrology’, ‘ecology’, and ‘environment’. Based on this we assessed the elements of planning for the target sites and obtained the following results. With regard to the aspect of humanities, planning urban hub green spaces was related to the satisfaction in leisure activities and the ‘quality of life’ that people expect to enjoy at parks or other green areas in general. Rather than focusing on direct and visible benefits, which might come from green infrastructure’s technological elements, people hoped that parks and green areas have macroscopic values. For hydrological characteristics, the ‘ecologically manages stormwater’ was applied the most in planning hub green spaces in cities, and it mainly took the form of technological elements or factors. Third, the planning elements pertaining to ecological characteristics were identified as a combination of strategies and technological elements that ‘reintroduces native plants’ and ‘habitat for wildlife’. As for the plans to instill eco-friendly aspects, the study found that the research on air, climate, weather, heat reaction, soil, energy efficiency, and use and application of resources is important. However, it was difficult to measure the potential quantitative benefits of ‘reusing or recycling materials’, ‘reducing urban heat’, and ‘cooling air temperature’. The result of this study is meaningful in that it can be used for the assessment of urban hub green spaces in the future.

To address the increase of weather hazards and the emergence of new types of such hazards, an optimization technique for three-dimensional (3D) representation of meteorological facts and atmospheric information was examined in this study as a novel method for weather analysis. The proposed system is termed as “meteorological and air quality information visualization engine” (MAIVE), and it can support several file formats and can implement high-resolution 3D terrain by employing a 30 m resolution digital elevation model. In this study, latest 3D representation techniques such as wind vector fields, contour maps, stream vector, stream line flow along the wind field and 3D volume rendering were applied. Implementation of the examples demonstrates that the results of numerical modeling are well reflected, and new representation techniques can facilitate the observation of meteorological factors and atmospheric information from different perspectives.

최근 사회기반시설(SOC)의 증가와 노후화에 따라 기존의 인력중심의 육안검사를 기반으로 한 안전점검은 경제성과 안전성, 효율성 면에서 한계를 가지고 있다. 본 연구에서는 육안점검의 한계를 개선하기 위해 딥러닝 모델 기반 물체를 탐지하는 기술을 활용하여 터널 콘크리트 균열을 자동으로 탐지하는 기술을 개발하였으며, 이를 실제 터널 영상에 적용하여 그 성능을 검증하였다.

강-콘크리트 합성구조의 성능을 확보하기 위해서는 전단연결재가 설치된 전단연결부에 대한 전단강도 분석이 필수적이다. 전단연결부의 전단거동을 효율적으로 예측하기 위하여, 전단연결부의 push-out test에 대한 유한요소해석을 수행하였다. 유한요소해석에는 범용 프로그램인 ABAQUS가 사용되었으며, 대상 실험체는 Y형 전단연결재가 적용된 강-콘크리트 전단연 결부이다. 유한요소해석에서는 대상 실험체를 구성하는 재료들의 비선형성을 고려하였고, 비선형해석의 수렴문제를 해결하기 위하여 준정적해석을 사용하였다. 본 연구에서 수행된 유한요소해석 결과를 바탕으로 하중-변위곡선과 전단강도를 기존 실험결과와 비교한 결과, 준정적해석을 이용한 유한요소모델은 기존 실험결과를 잘 반영하는 것을 확인하였다.

본 연구는 U형 복합보의 구조적 성능을 파악하기 위해 실험을 실시하였으며, 각 실험체의 휨 성능에 대한 실험값과 이론 값을 비교하였다. U형 복합보 단부에는 H 형강이 설치되고 중앙부분에는 U 형강이 설치되기 때문에 H 형강과 U 형강이 만나는 접합부에서의 원활한 응력전달이 중요하다. U형 복합보는 크게 3개 부분(U형보 단부의 H형강 부분, H형강과 U형보 가 만나는 부분, U형보만 존재하는 중앙부분) 구분할 수 있으며, U형 복합보의 중앙부와 하중작용점에 부착된 변형게이지의 변형률 값을 비교하여 중심축을 하중 단계별로 확인하였으며, 실험체의 하중단계별 변형률 분포를 확인하였다.

When problems occurred in the unstable and/or extreme terrain environment, formal field-driving robots were unable to provide any other options such as the transformation of the wheel and body structure, and so on. For such reason, this paper proposed a novel type of integrated wheel mechanism that can be operated as a conventional driving wheel mode and hybrid wheel-leg mode in order to be negotiated in an unstable terrain environment. The mechanical effect of the proposed variable wheel mechanism was analyzed considering the geometric constraint and power requirement of the actuator for the transformation. In addition, we designed and manufactured the prototype of field-driving robot, which reliably control the variable wheel shape. Finally, the effectiveness of the variable wheel mechanism was verified by preliminary experimental approach.

Recently, road maintenance is important for road performance and longevity in accordance with the increase of road infrastructure, so research on efficient damage detection has been actively carried out. In this study, we developed a technology to automatically detect the cracks on the highway road surface by using the road surface image of UAV and deep learning based object detection technology, which was applied to the actual highway image to verify its performance.

The purpose of this study is to calculate the moment of sharing ratio for each component of the U shaped composite beam. The experimental results show that the yield moment is 1,129.5 kN․m and the theoretical value based on the strain gages is 1,057 kN․m with a difference of about 7%. As a result, the share ratio of the slab of reinforced concrete and the bottom plate of the U shaped beam were found to be about 88%.

고준위폐기물을 처분하기 위한 심층 처분시설은 지하 500~1,000 m 깊이의 암반층에 설치된다. 심층 처분시스템의 구성 요 소로는 처분용기, 완충재, 뒷채움 및 근계 암반이 있다. 이 중 완충재는 심층 처분시스템에 있어 필수적인 요소인데, 완충재 는 지하수 유입으로부터 처분용기를 보호하고, 방사성 핵종 유출을 저지한다. 처분용기에서 발생하는 고온의 열량은 완충 재로 전파되기에 완충재의 열물성은 처분시스템의 안정성 평가에 상당히 중요하다고 할 수 있다. 완충재의 열전도도 규명 에 대한 연구는 많이 진행되고 있는 반면, 비열에 대한 연구는 미진한 상태이다. 따라서 본 연구에서는 국내 경주산 압축 벤 토나이트 완충재(KJ-II)에 대한 비열 추정 모델을 개발하고자 하였다. 압축 벤토나이트 완충재의 비열은 이중 탐침법을 이용 하여 다양한 포화도와 건조밀도에 따라 측정하였으며, 총 33개의 실험 데이터를 토대로 회귀분석을 이용하여 경주 압축 벤 토나이트의 비열을 추정할 수 있는 모델을 제시하였다.

본 시험은 논으로부터 밭으로 윤환한 2년차인 답전윤환밭과 연속밭에 풋옥수수 찰옥4호 등 8품종을 사용하여 윤환밭과 연속밭의 병충해 발생, 생육 및 수량특성 차이 구명은 물론 풋옥수수의 체계적인 유기농 답전윤환 재배기술을 위한 기초자료를 확립하고자 수행한 결 과는 다음과 같다. 유기농 답전윤환 시 주요 병해는 전반적으로 연속밭에 비해 윤환밭에서 발병률이 높았으며, 시험품종 중 저항성 품종으로 발병률이 2% 미만인 흑진주찰과 대학찰 로 판단되었다. 유기농 답전윤환 시 주요 충해인 조명나방 유충 피해는 전반적으로 연속밭 에 비해 윤환밭에서 피해주율이 높았으며, 시험품종 중 저항성 품종으로는 피해주율이 낮 은 찰옥4호와 흑점2호로 판단되었다. 유기농 답전윤환 시 수량은 윤환밭에서 연속밭의 85 % 수준으로 감소하였으며, 답전윤환밭에서는 찰옥4호가 789.0 kg/10a로 가장 수량이 많았 다. 내병성, 내충성, 수량을 종합 평가하면 유기농 답전윤환 시 적합 품종으로는 찰옥4호, 흑진주찰, 흑점2호로 판단된다.

This study examined the total glucosinolate (GSL) and isothiocyanate (ITC) contents according to different processing conditions; fresh Kimchi cabbage (Brassica rapa L. ssp. pekinensis), salted Kimchi cabbage and kimchi (storage temperature 4℃ and 20℃) using two different cultivars (Bomatnorang and Chunkwang). Four GSL peaks representing gluconapin, glucobrassicanapin, glucobrassicin and 4-methoxyglucobrassicin were detected in Kimchi cabbage by HPLC and HPLC/MS analysis. The total GSL contents of fresh Kimchi cabbage of Bomatnorang and Chunkwang were 21.37±1.06 μg/g dry weight (DW) and 20.96±3.33 μg/g DW, respectively. After salting, the total GSL contents of salted Kimchi cabbage decreased by 39% and 52% in Bomatnorang and Chunkwang, respectively. Finally, the total GSL contents of kimchi after storage at 20℃ decreased by 83% and 56% in Bomatnorang and Chunkwang, respectively. The extracted ITC contents were analyzed by GC/MS. Three ITC peaks were detected in Kimchi cabbage representing 2-phenylethyl ITC, 3-butenyl ITC and 4-pentenyl ITC. The 2-phenylethyl ITC levels increased during the salting process but this generally fell during storage at 20℃ as kimchi. The 3-butenyl ITC levels of Kimchi cabbage according to processing decreased rapidly due to salting and then decreased slowly during storage as kimchi. The 4-pentenyl ITC of Kimchi cabbage was lost during the salting process. The results for the change in GSL and ITC contents during the kimchi making process will be used in the food industry.

IPCC Guidelines have been updated after the first official announcement to get more precise estimation of GHG emissions. The goal of this study is to evaluate the implications of the IPCC Guidelines improvements including equations of country-specific parameter values for estimating GHG emissions for rice cultivation on the agricultural sector. In addition, we analyze the effects of emission factors associated with organic amendment applications. The results of this study are as follows; (1) the total GHG emissions of rice cultivation based on 1996 IPCC GL are 28% lower than those estimated by 2006 IPCC GL with the same year data; (2) GHGs can be reduced up to 60% through the assumption of organic fertilizer applications; (3) Jeonnam and Chungnam are the worst regions for GHG emissions on rice cultivation and Chungbuk shows the highest reduction rate of GHG emissions, about 40%.

A steel tubular member has been generally used for the offshore structure. Its stucutral performance can be decreased due to corrosion damage under severe corrosion environment In this study, to examine the compression performance of steel tubular member depending on corrosion thickness, damaged ratio, FE analyses were conducted and compared.

In this study, we investigated the relationship between the number of tourist visits to Taebaek and snowfall. We used the number of train passengers of Taebaek rail station and daily fresh snow records from Korea Railroad Corporation and Korea Meteorological Administration in the winter of 2010-2011 and 2013-2014. The results from our research show that heavy snowfall substantially attracts visitors who want enjoy snowy scenery whereas light snowfall has no influence on the number of tourist visits. In fact, according to our analysis, the number of visitors increases by 34% in the winter 2010-2011 and 72% in the winter of 2013-2014 at maximum in case of heavy snowfall events. The sharp increase in the number of visitors after the heavy snowfall reflects the positive effect of heavy snowfall, which creates beautiful scenery.