PURPOSES : This study investigates the factors affecting extra-long tunnel accidents by integrating data on tunnel geometry, traffic flow, and traffic accidents and derives the underlying implications to mitigate the severity of accidents. METHODS : Two processes centered on three key data points (tunnel geometry, traffic flow, and traffic accidents) were used in this study. The first is to analyze the spatial characteristics of extra-long tunnel traffic accidents and categorize them from multiple perspectives. The other was to investigate the factors affecting extra-long tunnel traffic accidents using the equivalent property-damage-only (EPDO) of individual accidents and the aforementioned data as the dependent and independent variables, respectively, by employing an ordered logistic regression model. RESULTS : Gyeonggi-do, Gyeongsangnam-do, and Gangwon-do are three metropolitan municipalities that have a significant number of extra-long tunnel accidents; Busan and Seoul have the most extra-long tunnel accidents, accounting for 23.2% (422 accidents) and 18.6% (339 accidents) of the 1,821 accidents that occurred from 2007 to 2020, respectively. In addition, approximately 70% of extra-long tunnel traffic accidents occurred along tunnels with lengths of less than 2 km, and Seoul and Busan accounted for over 60% of the top 20 extra-long tunnels with accidents. Most importantly, the Hwangryeong (down) tunnel in Busan experienced the most extra-long tunnel traffic accidents, with 77 accidents occurring during the same period. As a result of the ordered logistic regression modeling with EPDO and multiple independent variables, the significant factors affecting the severity of extra-long tunnel traffic accidents were determined to be road type (freeway, local route, and metropolitan city road), traffic flow (speed), accident time (year, summer, weekend, and afternoon), accident type (rear end), traffic law violations (safe distance violation and center line violation), and offending vehicles (van, sedan, and truck). CONCLUSIONS : Based on these results, the following measures and implications for mitigating the severity of extra-long tunnel traffic accidents must be considered: upgrading the emergency response level of all road types to that of freeways and actively promoting techniques for regulating high-speed vehicles approaching and traversing within extra-long tunnels are necessary. In addition, the emergency response and preparation system should be reinforced, particularly when the damage from extra-long tunnel traffic accidents is more serious, such as during the summer, weekends, and afternoons. Finally, traffic law violations such as safe distance and centerline violations in extra-long tunnels should be prohibited.
우리나라는 삼면이 바다로 이루어져 있고, 이에 따라 많은 해양 시설로 인한 위험유해물질이 배출되고 있으나, 배출관리 및 규제 시스템이 미비한 상황이다. 따라서, 위험유해물질(HNS) 관리를 위하여 효율적으로 데이터를 수집할 수 있는 시스템이 필요하 다. 본 연구에서는 HNS 데이터를 효율적으로 관리 및 저장하기 위한 데이터 표준화 시스템을 설계하고 이의 표준화 방안을 제시하고 자 한다.
The occurrence of sudden strike pest events in urban areas is increasing as global warming intensifies, consequently, re causing harmful impacts. Studies on these incidents are fewer in number and insufficient compared to research on other nuisances such as mosquitoes and flies. Therefore, we conducted a study on the development of a selective collection method, using a filter layer to establish a monitoring system for Ephemera orientalis (Ephemeroptera: Ephemeridae), a species frequently identified as a sudden strike pest. Three sampling points were selected along the Hangang River in Namyangju, where E. orientalis outbreaks occur. Prototypes, consisting of four layers and with a light source attached to attract insects, were installed at each sampling point. Sampling was performed every 30 minutes between 19:00 and 22:30 in the month of June. The filter interval of each layer was adjusted so that the collected mayflies were distributed into specific layers. To evaluate the collection efficiency in line with the materials and the filter intervals, the optimal collection efficiency was investigated by combining two types of layer materials (stainless and acrylic) and filter intervals (1-5 mm). The optimal conditions were as follows: The selective collection efficiency was found to be highest at 96.5% when the interval of the selective target filter was 2.0 mm and there was one upper filter.
The air dilution olfactory method to measure complex odors needs to store and carry odor samples from the field sampling until the analysis in laboratories. Until the analysis of sample in the laboratory, odor dilution factor (odor sensitivity) in the sample bag may decrease over time depending on the characteristics of each odor substances. This is one of the limitation for the air dilution olfactory method. Thus, the air dilution device enable to measure without loss in complex odors of samples. Recently, many studies on the performance test of on-site air dilution devices, i.e., field olfactometer, has been conducted to figure out the feasibility of the field olfactometers. In this study, seven odor samples were collected from five odor emission source sites. And comparative analysis with the air dilution olfactory method was carried out to assess the field applicability of the olfactometer. As results, the performance of the field olfactometer used in this study is regared as the affordable method. The dilution factors from between two methods showed the similar values, indicating low values of standard deviations. In order to ensure the accuracy and precision of measurement data using the field olfactometer, methodology minimized variables (that may affect measurement) needs to establish.
본 연구의 목적은 오수견의 구전적 설화를 중심으로 돌비의 출토 및 현 오수면 원동공원과의 연계성을 통해 오수의 지명적 가치를 분석하는 것이 다. 아울러 오수면에 위치한 의견공원, 김개인 생가 등 풍수적인 물형가치 를 찾아 구전에 합당한 공간을 설정하고, 이 설정이 구전적 오수의견(義犬) 과 부합하는 지리적 형상을 이해하고자 하였다. 오수의견은 구전이나 나름 의 역사성을 갖추고 있는 문헌적 사료(史料)가 있으며 그와 관련하여 오늘 날까지도 이 지역주민들의 사랑을 받고 있는 공간이기도 하다. 그러므로 오수면의 의견스토리가 담긴 공간성은 반려견문화 세계화에 따라서 더욱 그 의미의 확장성을 보일 수 있다. 이러한 관점에서 오수면의 정체성과 지 명 그리고 전반적인 인문학적 연구가 더욱 필요할 것이다. 또한 의견의 구 전적 이야기와 합치하는 풍수적 의견물형(義犬物形)을 더하고 구전적 오수 견 이야기의 토대를 돌비출현과 연관 지어 스토리의 완성적 공간을 확장하 였다. 본 연구는 단순히 구전적 이야기로만 전해오던 인간과 반려견(의견) 과의 인격적 애정관계를 통해서 그들 간의 생명관을 고찰함과 동시에 오수 의견 이야기의 실제적 역사로서 그 가능성을 살펴보고자 하였다. 또한 오 수의견 이야기의 주 무대로 알려진 오수면의 지명적 정체성을 알아보고 그 의미를 바탕으로 오수의견과의 연결성 있는 스토리를 찾아보고자 하였다.
The development of automated bottle cultivation systems has facilitated the large-scale production of Pleurotus ostreatus, a commonly cultivated oyster mushroom species in South Korea. However, as the consumption of this product is decreasing and production quantities are exceeding demand, farmers are seeking various other mushroom types and cultivars. In response to this, we have developed a new oyster mushroom cultivar named 'Sena'. This high-yielding cultivar has a white pileus and excellent quality. The white oyster mushroom cultivars 'Goni' and 'Miso' were selected as parental strains from the genetic resources of the National Institute of Horticultural and Herbal Science’s Mushroom Division. By crossing their monokaryons, hybrids were developed and subjected to cultivation trials and characteristic evaluations to select the superior cultivar. The optimal temperature for 'Sena' mycelial growth is 25–30°C, with inhibition occurring at temperatures above 30°C, whereas the temperature for mushroom growth is 14–18°C. The mushrooms grow in clusters, with the white pileus having a shallow funnel shape. Optimal mycelial growth occurs in malt extract agar medium. When cultivated in 1,100 cc bottles, the 'Sena' cultivar had 35 available individuals, surpassing the number 16 available from the control cultivar 'Goni'. The yield per bottle also increased by approximately 157 g, a 24% increase over the control cultivar amount. When 300 g samples of harvested mushrooms were packed and stored at 4°C in a cold storage facility for 28 days, the weight loss rate of ‘Sena’ was approximately 4.22%, lower than that of 'Goni'. Moreover, the changes in pileus and stipe whiteness (measuring 6.99 and 8.33, respectively) were also lower than those of the control cultivar. Since the appearance of a white cap is crucial for quality assessment, the 'Sena' cultivar is superior to the 'Goni' cultivar in terms of both weight and quality after undergoing lowtemperature storage.
A new brown variety of Flammulina velutipes, referred to as ‘Asakgold,’ was bred by crossing two monokaryons isolated from the “Geumhyang2ho” and “Garlmoe” varieties. The pileus color of the new variety is light brown and its shape is hemispherical. During bottle cultivation, the period necessary for mycelial growth was 40 days, 9 days for primordia formation and 15 days for fruiting body growth. The total cultivation period was 64 days, which was similar to that of the control variety “Yeoreumhyang1ho.” The pileus of the new variety was similar and the stipe was thinner and longer than that of the control. The number of valid stipes per bottle was 495, which was 37 % higher than that of the control (362), and the yield was 214 g, 16 % higher than that of the control (185 g). The -glucan content was 28.69 %, which was observed to be 1.6 times more than that of the control.
Recently, Free-Form and Irregular Shape high-rise buildings are constructed by IT technology development. Tilted shaped high-rise building which is one of Irregular shape high-rise buildings can cause lateral displacement by gravity load and lateral load due to tilted elevation shape. Therefore, it is necessary to review the behavior and structural aspects of the Tilted shape high-rise building by gravity load. In this paper, the dynamic characteristics of a tilted structure with a dual-core were analyzed with the core location as a design variable, and response behavior, vulnerable members, and vulnerable layers to earthquake loads were analyzed. As a result of the analysis, as the location of the core moved in an tilted direction, the eccentric distance and eccentric load decreased, reducing the axial force of the vertical members. However, the location of the core had little effect on the response.
최근 국내에서 외래 곤충인 (가칭)마른나무흰개미(Cryptotermes domesticus)가 서울에 위치한 주택에서 발견되었다. 이 종은 국내에 정착할 경우 잠재적으로 목재나 목조건물에 피해를 줄 수 있어 시급한 국내 발생 조사가 필요하다. 본 연구에서는 종 분포 모델 기법을 활용하여 마른나 무흰개미의 정착 가능성과 관련된 기후적합성을 추정하는 것을 목표로 하였다. 문헌 자료를 바탕으로 전세계 분포 정보를 수집하고, 생물기후변 수를 활용하여 4개의 모델링 알고리즘으로 기후적합성 예측 모델을 구동하였다. 개발한 모델들의 결과를 종합하여 최종적으로 마른나무흰개미 의 평균 발생 확률로 표현되는 앙상블 모델을 개발하였다. 그 결과 마른나무흰개미는 열대 지방에서에서 해양성 기후를 보이는 연안이나 도서지 역에서 기후적합성이 높을 것으로 예상되었다. 국내에서는 기후적합성이 전반적으로 낮을 것으로 추정되었다. 하지만, 마른나무흰개미의 정착 및 확산 가능성을 염두해두고, 최근 발생이 보고된 지점을 중심으로 정밀 역학 조사가 필요할 것으로 보인다.
본 연구의 목적은 남자 대학 엘리트 조정선수의 2000 m 로잉 에르고미터 수행 후 저온침수 처 치를 통해 혈중 젖산, LDH, MDA 및 SOD의 변화에 긍정적인 영향을 주어 피로 회복에 미치는 영향을 구명하는 데 있다. 이에 남자 대학 엘리트 조정선수 10명을 대상으로 고강도 로잉 에르고미터 2,000 m 수 행 후 비 처치와 저온 침수 처치의 효과를 비교하였다. 측정 변인들에 대한 결과를 검증하기 위해 처치 및 시기 간 상호작용 효과를 분석하기 위해 ANOVA를 실시하였고 각 항목별 유의수준 .05로 설정하여 다음 의 결과를 도출하였다. 젖산은 시기 간 주효과가 나타났고(p<.001) 그룹 내 시기별 차이가 났다(p<.001). 또한, LDH는 그룹 내 시기별 차이가 나타났다(p<.05). MDA는 그룹×시기 간 상호작용 효과가 나타났고 (p<.05), 그룹 간(p<.05), 시기 간(p<.001) 주효과가 나타났다. SOD는 그룹 간, 시기 주효과가 나타났고 (p<.05) 회복 30분 후 그룹 간 차이가 나타났다(p<.05). 이를 종합해 볼 때, 본 연구에서 실시한 저온침수처치가 조정 선수의 혈중 피로 물질, 활성산소 및 항산화 효소에 유의한 효과를 나타냈다. 따라서 운동선수 의 고강도 훈련 후 저온침수를 적극 활용할 것을 권장한다.
본 연구는 한국 여성의류소비자의 한국형아유르베다 성격유형과 의류 구매후기의 관계연구를 하는 것이 목적이며, 이러한 연구 목적을 위해 연구대상은 수도권 거주하는 20대 이상 설문 대상자 542명이었으며, 이 중 최종적으로 불성실한 응답을 제외한 519부를 본연구의 자료로 사용 하였다. SPSS 26프로그램을 통해 주요변수의 타당성, 신뢰성을 확보하 기 위하여 탐색적 요인분석, 인구학적 특성을 확인하기 위해 빈도분석, 성격유형에 따른 구매후기 점수의 차이를 확인하기 위해 세 집단 이상의 평균차이를 확인할 수 있는 일원배치분산분석(One-way ANOVA)을 실 시한 분석결과는 여성소비자의 한국형아유르베다 기본심리유형 중 하나 인 카파형(K)이 피타형(P)에 비해 구매후기를 중요하게 본다는 것을 알 수 있다. 이는 피타형(P)이 카파형(K)에 비해 구매후기를 중시하는 경향 이 낮은 이유는 자기주장이 강하고 주도적이며, 강한신념을 지니고 믿음 이 확고한 성격을 갖고 있는 것과 관계가 있음을 확인할 수 있다. 연령 을 구분하여 분석한 결과, 20~30대에서 유의한 차이가 나타났으며, 사후 검정 결과 피타형(P)의 평균보다 카파형(K)의 평균이 높은 것으로 확인되 었고 다중회귀분석을 통해서도 유사한 결과가 도출되었다. 이는 기성세 대에 비해 20~30대에서 구매후기를 중요시하는 경향은 모바일을 사용한 온라인, 디지털 환경에 익숙하기 때문이라 분석된다. 따라서 본 연구는 여성소비자의 성격유형과 구매결정후기 관계를 분석함으로써 마케팅 및 경영적 기초자료로 활용할 수 있을 것으로 사료된다.
Recently, there has been an increasing demand for independent suspension systems in commercial vehicles, and various researches related to this trend are currently underway. In this study, as part of an effort to localize the independent suspension system for commercial vehicles, a preceding study was conducted to convert the existing forging process into a casting process. The structural stability of the developed product was evaluated by performing stress analysis on both forging and casting materials. In order to compensate for the low yield characteristics of the casting material, design improvements were made to lower the maximum stress level based on numerical simulations.Additionally, Lightweight design was performed, capitalizing on the inherent design flexibility offered by casting products. As a result, it was confirmed that the developed product exhibited similar stress characteristics level to the existing product, along with a weight reduction of approximately 5%.
In factory automation, efforts are being made to increase productivity while maintaining high-quality products. In this study, a CNN network structure was designed to quickly and accurately recognize a cigarette located in the opposite direction or a cigarette with a loose end in an automated facility rotating at high speed for cigarette production. Tobacco inspection requires a simple network structure and fast processing time and performance. The proposed network has an excellent accuracy of 96.33% and a short processing time of 0.527 msec, showing excellent performance in learning time and performance compared to other CNN networks, confirming its practicality. In addition, it was confirmed that efficient learning is possible by increasing a small number of image data through a rotation conversion method.
Thermite welding is an exceptional process that does not require additional energy supplies, resulting in welded joints that exhibit mechanical properties and conductivity equivalent to those of the parent materials. The global adoption of thermite welding is growing across various industries. However, in Korea, limited research is being conducted on the core technology of thermite welding. Currently, domestic production of thermite powder in Korea involves recycling copper oxide (CuO). Unfortunately, controlling the particle size of waste CuO poses challenges, leading to the unwanted formation of pores and cracks during thermite welding. In this study, we investigate the influence of powder particle size on thermite welding in the production of Cu-thermite powder using waste CuO. We conduct the ball milling process for 0.5–24 h using recycled CuO. The evolution of the powder shape and size is analyzed using particle size analysis and scanning electron microscopy (SEM). Furthermore, we examine the thermal reaction characteristics through differential scanning calorimetry. Additionally, the microstructures of the welded samples are observed using optical microscopy and SEM to evaluate the impact of powder particle size on weldability. Lastly, hardness measurements are performed to assess the strengths of the welded materials.