• Title/Summary/Keyword: space vehicles

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Analysis of Safety and Mobility of Expressway Land Control System (길어깨차로제 시행에 따른 안전성 및 이동성 분석)

  • Park, Sung-ho;Lee, Yoseph;Kang, Sungkwan;Cho, Hyonbae;Yun, Ilsoo
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.20 no.3
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    • pp.1-19
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    • 2021
  • The domastic hard shoulder running(HSR) System has been gradually expanding since its initial implementation in September 2007 with the aim of increasing capacity and resolving congestion. Hard Shoulder is used as a space for driver's visual comfort and a place for vehicles to evacuate in case of emergency, but it is replaced by a space for driving when the HSR System is implemented. Therefore, it was intended to determine the improvement effect before and after implementation of the HSR system through safety analysis and mobility analysis. The safety analysis analyzed the impact of traffic accidents by comparing HSR sections and similar sections. The mobility analysis was to determine the improvement effect by quantifying the speed and traffic volume changes before and after HSR System implementation. According to safety yanalysis, there is no effect of reducing traffic accidents when implementing the HSR System. In mobility analysis, the implementation of the HSR System significantly improved the speed of traffic during peak hours and significantly reduces slow and delay hours.

An Experimental Study on the Applicability of UAV for the Analysis of Factors Influencing Rural Environment - Focusing on Photovoltaic Facilities and Vacant House in Galsan-Myeon, Hongseong-gun - (농촌 공간 환경영향요인 분석을 위한 무인항공기 적용 가능성에 관한 실험적 연구 - 홍성군 갈산면의 태양광 발전시설과 빈집을 중심으로 -)

  • An, Phil-Gyun;Eom, Seong-Jun;Kim, Su-Yeon;Kim, Young-Gyun
    • Journal of the Korean Institute of Rural Architecture
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    • v.24 no.1
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    • pp.9-17
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    • 2022
  • Rural spaces are increasingly valuable as areas for introducing renewable energy infrastructure to achieve carbon neutrality. Rural areas are the living grounds of rural residents, and the balance of conservation and development for rural areas is important for the introduction of reasonable facilities. In order to maintain a balance between development and preservation and to introduce reasonable renewable energy facilities, it is necessary to develop a current status survey and an effective survey method to utilize a space capable of introducing renewable energy facilities such as idle land and vacant houses. Therefore, this study was conducted to verify the readability using an unmanned aerial vehicle, and the main results are as follows. The detection of photovoltaic power generation facilities using unmanned aerial vehicles was effective in analyzing the location and area of photovoltaic panels located on the roofs of buildings, and it was possible to calculate the expected power generation by region through the area calculation of photovoltaic panels. The vacant house detection can be used to select an investigation target for an vacant house condition survey as it can identify damage to buildings that are expected to be empty houses, management status, and electricity supply facilities through aerial photos. It is judged that the unmanned aerial vehicle detection capability can be utilized as a method to improve the efficiency of investigation and supplement the data related to solar power generation facilities and vacant houses provided by public institutions. Although this study detected the status of solar power generation facilities and vacant houses through high-resolution aerial image analysis, as a follow-up study, automatic measurement methods using the temperature difference of solar power generation facilities and general characteristics of vacant houses that can be read from the air were investigated. If the deriving research is carried out, it is judged that it will be possible to contribute to the improvement of the accuracy of the detection result using the unmanned aerial vehicle and the expansion of the application range.

Training a semantic segmentation model for cracks in the concrete lining of tunnel (터널 콘크리트 라이닝 균열 분석을 위한 의미론적 분할 모델 학습)

  • Ham, Sangwoo;Bae, Soohyeon;Kim, Hwiyoung;Lee, Impyeong;Lee, Gyu-Phil;Kim, Donggyou
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.23 no.6
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    • pp.549-558
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    • 2021
  • In order to keep infrastructures such as tunnels and underground facilities safe, cracks of concrete lining in tunnel should be detected by regular inspections. Since regular inspections are accomplished through manual efforts using maintenance lift vehicles, it brings about traffic jam, exposes works to dangerous circumstances, and deteriorates consistency of crack inspection data. This study aims to provide methodology to automatically extract cracks from tunnel concrete lining images generated by the existing tunnel image acquisition system. Specifically, we train a deep learning based semantic segmentation model with open dataset, and evaluate its performance with the dataset from the existing tunnel image acquisition system. In particular, we compare the model performance in case of using all of a public dataset, subset of the public dataset which are related to tunnel surfaces, and the tunnel-related subset with negative examples. As a result, the model trained using the tunnel-related subset with negative examples reached the best performance. In the future, we expect that this research can be used for planning efficient model training strategy for crack detection.

An Analysis of Threat Factors for Strengthen Maritime Safety around Delphi/AHP-Based Launch Site and Flight Paths (Delphi/AHP 기반 발사장 주변 및 비행경로의 해상안전 강화를 위한 위협요인 분석)

  • Ahn-Tae Shin;Byung-Mun Park;Hun-Soo Byun
    • Korean Chemical Engineering Research
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    • v.61 no.2
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    • pp.208-216
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    • 2023
  • In this study, using the Delphi method, 20 responses to 4 questions (need for launch safety control, top-priority considerations for ensuring public safety during launch, necessary improvements for securing maritime safety, and maritime safety threat factors) regarding launch vehicles and public safety were obtained from experts, and their importance was evaluated to analyze the factors that threaten the reinforcement of maritime safety around launch sites and flight paths when launching. According to the results of an analytic hierarchy process (AHP) analysis, the consistency ratio of the four questions was 4.8%, which is lower than CR ≤ 0.1(10%), and the consistency percentage of the lower measurement indicators was 3.9~5.7%. The derived importance and priority of maritime safety threat factors during launching were in the following order: Substantial human and physical damage in case of launch accidents(0.36), Prepare legal bases (e.g., penalty details) regarding maritime control(0.32), Secure the safety of personnel, equipment, and facilities in danger zone(0.31), Unauthorized entry of vessels in maritime control zones and non-compliance to restrictions(0.30). This article can serve as a reference for strengthening maritime safety in areas around launch sites and flight paths.

Development of Estimation Models for Parking Units -Focused on Gwangju Metropolitan City Condominium Apartments- (주차원단위 산정 모형 개발에 관한 연구 -광주광역시 공동 주택 아파트를 대상으로-)

  • Kwon, Sung-Dae;Ko, Dong-Bong;Park, Je-Jin;Ha, Tae-Jun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.34 no.2
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    • pp.549-559
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    • 2014
  • The rapid expansion of cities led to the shortage of housing in urban areas. The government compensated for this shortage through large scale residential developments that increased the housing supply. The supply of condominium apartments remains above 83% of the entire housing supply, and the proportion of apartments are at a steady increase, at about 50%. Due to the increase, illegally parked cars resulting from the shortage of parking spaces within the apartment complex have become increasingly problematic as they block the transit of emergency vehicles, and heighten the tension among neighboring residents in obtaining a parking space. Especially, the future residents are considered to plan the parking based on the estimated demand for parking. However, the parking unit method utilized to estimate the parking demand accounts for the exclusive use of space, which is believed to be far from the parking demands in reality. The reason for this discrepancy is that, as the number of households decrease, and area of exclusive space is expanded, the planned parking increases. On the other hand, when the number of households increase, and the area of exclusive space is reduced, the planned parking decreases, thus methods to recalculate the parking units based on estimated parking demand is an urgent concern. To estimate the parking units based on condominium apartments, this study first examined the existing research literature, and appointed the field of investigation to collect the necessary data. In addition, field study data and surveys collected and analyzed, in order to identify the problems underlying parking units, and problems regarding the current traffic impact assessment parking unit calculation method were deduced. Through identifying the influential factors on parking demand estimates, and performing a factorial analysis based on the collected data, the variables were selected in relation to the parking demand estimates, to develop the parking unit estimate model. Finally, through comparing and verifying the existing traffic impact assessment parking unit estimate against the newly developed model using collected data, a far more realistic parking unite estimate was suggested, reflecting the characteristics of the residents. The parking unit estimate model developed in this study is anticipated to serve as the guidelines for future parking lot legislature, as wel as the basis to provide a more realistic estimate of parking demands based on the resident characteristics of an apartment complex.

Characteristics of Satellite-Based CO/CO2, CO/NO2 Ratio in South Korea and China (한국과 중국의 도시별 위성기반 CO/CO2, CO/NO2 비율 특성)

  • Jieun Yu;Jaemin Kim;Jin Ah Jang;Jeong-Ah Yu;Seung-Yeon Kim;Yun Gon Lee
    • Korean Journal of Remote Sensing
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    • v.39 no.2
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    • pp.129-142
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    • 2023
  • This study analyzed the ratio of carbon monoxide (CO) and carbon dioxide (CO2), CO and nitrogen dioxide (NO2) for cities and regionsin Korea and China using column-averaged carbon dioxide dry-air mole fraction (XCO2) of the Orbiting Carbon Observatory-2/3, CO and NO2 vertical column density (named XCO, XNO2 in thisstudy) of TROPOspheric monitoring instrument from April 2018 to April 2022, and presented the relationship between socioeconomic indicators (population, number of vehicles, Gross Regional Domestic Product) and ratio, and differences in characteristics between Korea and China. First, CO2 and CO were analyzed after calculating ΔXCO2 and ΔXCO removing the background value and trend line due to the difference in atmospheric residence time of three gaseous substances (CO2, CO, and NO2). Comparing the three values by regions, ΔXCO and ΔXCO2 were relatively higher in China and XNO2 were higher in Korea and the ratio of both values (ΔXCO/ΔXCO2, ΔXCO/XNO2) was higher in China than in Korea. ΔXCO/ΔXCO2, ΔXCO/XNO2 and socioeconomic indicators have a positive correlation suggesting that the concentration of air pollutants and greenhouse gases is higher as the city is large and the economic activity is active. Regarding the differences in the ratio characteristics of Korea and China, the relationship between ΔXCO and ΔXCO2 showed a negative correlation in Korea and a positive correlation in China. When the relationship between ΔXCO and XNO2 was examined for summer and winter, the change of ΔXCO by season was not significant in Korea, whereasthe change of ΔXCO and XNO2 by season waslarge in China resulting in the relationship between two countries appeared differently. These results suggest that seasonal variability and national emission characteristics should be considered in the process of analyzing the ratio of greenhouse gases to air pollutants.

An Evaluation of Outdoor Living Environments for Senior Citizens - Focused on the Prospective Seniors and Senior Citizens in Daejeon - (고령자를 위한 거주지 외부환경 평가 - 대전시 거주 준고령자 이상을 대상으로 -)

  • Lee, Shi-Young;Lee, Hei-Jung;Lim, Byung-Ho;Shim, Joon-Young
    • Journal of the Korean Institute of Landscape Architecture
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    • v.39 no.4
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    • pp.39-48
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    • 2011
  • Korea is rapidly becoming an aging society. This study aims to examine the existing conditions of outdoor living environments to assist a healthy lifestyle for senior citizens and to determine the most influential factor in a senior-friendly outdoor space as well as to suggest improvements in existing conditions focused on the prospective senior population. This study relied on two methods: a descriptive method of researching publications and related scholastic writings and an empirical study that included a survey of present conditions and interviews with the prospective seniors and senior citizens in Daejeon. Conditions of outdoor living environments for seniors were found to be more than adequate in general. But some factors evaluated as low must be carefully tailored for seniors. First, the study showed that seniors evaluated as highest the 'use of a walkway' for a stroll and stayed outside for 1~2 hours at a time. Many vehicles parked in walkways were the most inconvenient factors in going for a walk. Second, the study showed that the evaluation of outdoor space was about average and 'sociality' was evaluated as the lowest. Third, the study showed that men evaluated lower than women 4 items: 'use and convenience of a wheelchair', 'night lighting', 'discrimination of signage at nighttime' and 'trees'. Respondents above the age of 66 are more uncomfortable with items such as 'slippery walking surface', 'stair handrail', 'discrimination of signage at nighttime' and 'direction of apartment complex' while respondents above the age of 80 are more uncomfortable with items of 'slippery walking surface', 'stair handrail' and 'discrimination of signage at nighttime'. Fourth, the evaluation by existing housing patterns was statistically significant in 20 of 22 evaluated items. This means that residents in apartment complex evaluated as high these items in general. In this study, existing outdoor living environments for the elderly did not display any immediately serious issues in the overall evaluation items. Assuming, however, that the aging population will quickly increase in the next ten years, items which are evaluated as low in descriptive statistics and items which give inconvenience to the elderly above the age of 80 in particular will need to be the first areas to be improved.

Development of a deep-learning based tunnel incident detection system on CCTVs (딥러닝 기반 터널 영상유고감지 시스템 개발 연구)

  • Shin, Hyu-Soung;Lee, Kyu-Beom;Yim, Min-Jin;Kim, Dong-Gyou
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.19 no.6
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    • pp.915-936
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    • 2017
  • In this study, current status of Korean hazard mitigation guideline for tunnel operation is summarized. It shows that requirement for CCTV installation has been gradually stricted and needs for tunnel incident detection system in conjunction with the CCTV in tunnels have been highly increased. Despite of this, it is noticed that mathematical algorithm based incident detection system, which are commonly applied in current tunnel operation, show very low detectable rates by less than 50%. The putative major reasons seem to be (1) very weak intensity of illumination (2) dust in tunnel (3) low installation height of CCTV to about 3.5 m, etc. Therefore, an attempt in this study is made to develop an deep-learning based tunnel incident detection system, which is relatively insensitive to very poor visibility conditions. Its theoretical background is given and validating investigation are undertaken focused on the moving vehicles and person out of vehicle in tunnel, which are the official major objects to be detected. Two scenarios are set up: (1) training and prediction in the same tunnel (2) training in a tunnel and prediction in the other tunnel. From the both cases, targeted object detection in prediction mode are achieved to detectable rate to higher than 80% in case of similar time period between training and prediction but it shows a bit low detectable rate to 40% when the prediction times are far from the training time without further training taking place. However, it is believed that the AI based system would be enhanced in its predictability automatically as further training are followed with accumulated CCTV BigData without any revision or calibration of the incident detection system.

A study on the fire characteristics according to the installation type of large smoke exhaust port in a small cross sectional tunnel fire (소단면 대심도 터널 화재시 대배기구의 설치형태에 따른 화재특성 연구)

  • Choi, Pan-Gyu;Baek, Doo-San;Yoo, Ji-Oh;Kim, Chang-Yong
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.21 no.1
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    • pp.201-210
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    • 2019
  • Recently, due to the efforts to mitigate traffic congestion and expansion of space efficiency, the construction of underground roads has been increased in big-scale cities. Since tunnels in the city have a higher chance for a fire leading to a great tragedy during a severe traffic jam than mountain tunnels, it is highly likely that it will be constructed as a tunnel, having a small cross section, for small vehicles. However, if they are constructed as such small-vehicle tunnels, it would be possible to reduce the design fire intensity while the concentration of harmful gases would increase due to a reduction in the small cross sectional area, led by a decrease in the tunnel height. In this study, behaviors of fire smoke by the installation interval and format of large-scale exhaust-gas ports were examined and compared in the analysis of temperatures and CO concentrations of a tunnel and its results were as the following. Although there were no significant differences in the smoke spreading distance between installation intervals, but in this study, 100 m was found to be the most effective installation interval. The smoke exhaustion performance was found to be excellent in the order of $4m{\times}3m$, $6m{\times}2m$, and $3m{\times}2m$ (2 lane) of the smoke spreading distance. Although there was no significant difference in the smoke spreading distance between formats of large-scale exhaust-gas ports, it was found that the smoke spreading distance was larger than other cases when it was $3m{\times}2m$ in the fire growing process. The analysis of smoke spreading distances by the aspect ratio showed that a smoke spreading distance was shorted when its the smoke spreading distance was found to be shorter when its traverse distance was relatively longer than its longitudinal distance.

Derivation of Constraint Factors Affecting Passenger's In-Vehicle Activity of Urban Air Mobility's Personal Air Vehicle and Design Criteria According to the Level of Human Impact (도심항공모빌리티 비행체 PAV 탑승자 실내행위에 영향을 미치는 제약 요소 도출 및 인체 영향 수준에 따른 설계 기준)

  • Jin, Seok-Jun;Oh, Young-Hoon;Ju, Da Young
    • Science of Emotion and Sensibility
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    • v.25 no.1
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    • pp.3-20
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    • 2022
  • Recently, prior to the commercialization of urban air mobility (UAM), the importance of R&D for air transportation-related industries in urban areas has significantly increased. To create a UAM environment, research is being conducted on personal air vehicles (PAVs). They are key means of air transportation, but research on the physical factors influencing their passengers is relatively insufficient. In particular, because the PAV is expected to be used as a living space for the passengers, research on the effects of the physical elements generated in the PAV on the human body is essential to design an interior space that supports the in-vehicle activities of the passengers. Therefore, the purpose of this study is to derive the constraint factors that affect the human body due to the air navigation characteristics of the PAV and to understand the impact of these constraint factors on the bodies of the passengers performing in-vehicle activities. The results of this study indicate that when the PAV was operated at less than 4,000 ft, which is the operating standard, the constraint factors were noise, vibration, and motion sickness caused by low-frequency motion. These constraint factors affect in-vehicle activity; thus, the in-vehicle activities that can be performed in a PAV were derived using autonomous cars, airplanes, and PAV concept cases. Furthermore, considering the impact of the constraint factors and their levels on the human body, recommended constraint factor criteria to support in-vehicle activities were established. To reduce the level of impact of the constraint factors on the human body and to support in-vehicle activity, the seat's shape and built-in functions of the seat (vibration reduction function, temperature control, LED lighting, etc.) and external noise reduction using a directional speaker for each individual seat were recommended. Moreover, it was suggested that interior materials for noise and vibration reduction should be used in the design of the interior space. The contributions of this study are the determination of the constraint factors affecting the in-vehicle PAV activity and the confirmation of the level of impact of the factors on the human body; in the future, these findings can be used as basic data for suitable PAV interior design.