• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.11
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• pp.3523-3543
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• 2022

Autonomous vehicles are gradually being regarded as the mainstream trend of future development of the automobile industry. Autonomous driving networks generate many intensive and delay-sensitive computing tasks. The storage space, computing power, and battery capacity of autonomous vehicle terminals cannot meet the resource requirements of the tasks. In this paper, we focus on the task scheduling problem of autonomous driving in software-defined edge networks. By analyzing the intensive and delay-sensitive computing tasks of autonomous vehicles, we propose an emotion model that is related to task urgency and changes with execution time and propose an optimal base station (BS) task scheduling (OBSTS) algorithm. Task sentiment is an important factor that changes with the length of time that computing tasks with different urgency levels remain in the queue. The algorithm uses task sentiment as a performance indicator to measure task scheduling. Experimental results show that the OBSTS algorithm can more effectively meet the intensive and delay-sensitive requirements of vehicle terminals for network resources and improve user service experience.

• International journal of advanced smart convergence
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• v.11 no.1
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• pp.94-100
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• 2022

It is common for commercial vehicles to make the top part according to the use after making the bear chassis, and to connect various devices with the bear chassis. Various brackets used in bear chassis for the development of all automobiles, including commercial vehicles, play a role of connecting the components required for driving and operating the car to the car body. In commercial vehicles, components necessary for operation are installed in the bear chassis; that is, the bear chassis of commercial vehicles is a space where the devices required for driving and operating the vehicle are installed. The devices required for the configuration of the vehicle are drive, brake, exhaust and steering, etc. These devices are basically connected to the body, the front axis, or the rear axis. The part interlinking the apparatuses required for the vehicle drive to the car body or axis is bracket. In this study, we analyzed the boundary conditions to evaluate the stability of the three brackets that connect the components of the car to the front axis of the new type of 30-seater bus in the development process. In order to analyze the boundary conditions, the boundary conditions according to the driving condition of the vehicle were classified. For stress analysis to evaluate the stability of brackets according to the driving state of the vehicle, it is reasonable to give the bracket a boundary condition of harsh conditions.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.2
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• pp.138-151
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• 2018

In this study, development information and technologies for reusable launch vehicles were surveyed. We investigated the reusable launch vehicles developed in various countries and analyzed their recovery technologies. In particular, we focus on the technologies of the Falcon 9 of SpaceX and the New Shepard of Blue Origin, which have succeeded in several flight experiments. Moreover, we explain the control algorithms for each flight condition. Finally, we discuss the reusable technologies that can be applied to the Korean Space Launch Vehicle to reduce the launch cost.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.12
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• pp.1069-1075
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• 2017

With the recent development of space technology, the satellite market, especially the small satellite market, is growing globally. As the satellite market continues to grow, the launch vehicle market is also growing, and demand for low-cost launches is increasing. There are a number of options for low-cost launches, including development of engine that uses low-cost propellants, product and transportation cost savings, but the most effective way to reduce launch costs is to reuse the used launch vehicles. USA's Space Shuttle, a famous rocket as manned spacecraft, could be referred as the start of reusable launch vehicle. However, Space Shuttle had limited reusable parts and it was very expensive even though it is a reusable launch vehicle because of its low efficiency. In recent years, aiming at a real reusable launch vehicle, reusable launch vehicle for commercial purposes have been developed around USA's SpaceX and Blue Origin, and re-landing tests were successfully accomplished. In addition, SpaceX successfully did the re-using of first-stage launch vehicle that had been succeeded in re-landing already. In accordance with this trend, countries such as Europe and India are also concentrating on the study of reusable launch vehicles. Including Blue Origin, companies like Virgin Galactic and XCOR in the United States, are also trying to commercialize the same reusable technology as the private manned space tourism. Confirmation of these technology trends is essential, because the re-use technology could change the landscape of the global launch vehicle market.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.3
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• pp.593-601
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• 2017

With the rapid industrial development and national economic advance since 1970, the national income of Korea has sharply increased. As a result, issues regarding city expansion, urban concentration, increase in the number of registered motor vehicles, and increase in traffic have caused transportation issues such as traffic congestion and problems with parking. Especially, enforcement ordinances and rules have been established on installation and management of parking lots to solve problems with parking which are raised as social problems such as conflict with neighbors but the flexible calculation of legal parking space has the limitations because of the diversity and complex functionality of purposes of facilities. Accordingly, this study attempted to supplement such demerit of the parking space demand forecast method based on the legally required number of parking spaces and average unit requirement in the parking space supply. This study estimated the required number of parking spaces by analyzing existing literature, collecting field research data, and analyzing the factors that have an impact on the parking demand. Also, it compared the required number of parking spaces based on the average unit requirement as well as the required number of parking spaces by the forecast model based on the cumulative number of motor vehicles parked. The result was that the required number of parking space based on average unit requirement was less than the cumulative number of motor vehicles parked by 9.99%. Meanwhile, the required number of parking spaces by the forecast model was more than the cumulative number of motor vehicles parked by 4.37%. Therefore, it is believed that the parking space forecast model is more efficient than the others in estimating there quired parking space. The parking space forecast model of this study consider different environmental factors to enable practical parking demand forecast considering the local characteristics and thus supply the parking space in an efficient way.

• Bulletin of the Korean Space Science Society
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• 2006.04a
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• pp.51-51
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• 2006

• International Journal of Aeronautical and Space Sciences
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• v.3 no.1
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• pp.19-29
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• 2002

Decentralized filtering for a formation flight instrumentation system by INS/GPS integration is considered in this paper. An elaborate tuning method of the measurement noise covariance is suggested to compensate modeling errors caused by decentralizing the extended Kalman filter. It does not require large data transfer between formation vehicles. Covariance analysis exhibits the superior performance of the proposed approach when compared with the existent decentralized filter and the global filter, which has the target-filter performance.

• Journal of the Korea Society of Computer and Information
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• v.18 no.11
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• pp.145-151
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• 2013

This research is to suggest a method for investigating car number plates among the information managed in parking facilities. The investigation of car number plate is generally used to know how long vehicles are parked. Also, it can provide the information about the parking turnover rate and the mean parking duration of parked vehicles. This research performs the investigation using cameras at a distance of time. That is, the given distance of time from cameras is assigned to each parked vehicle, and then it can find the mean parking time of parked vehicles. Also, it can check the parking turnover rate of parked vehicles at a space unit of parking lot in an hour. The information such as the mean parked duration and the parking turnover rate of parked vehicles taken from this method is helpful to find and understand the inefficient use of parking facilities. With this suggested method, this research attempted to check the mean parking duration and the parking turnover rate of parked vehicles.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.29 no.4
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• pp.67-77
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• 2021

Space development has been led by the state due to huge investment, risks of development failure, and restrictions on international cooperation on technology development and transfer. For this reason, it has been developed mainly by some advanced countries and industrial network formed among them. However, Korean space industry is being promoted by the successful launch of 'KSLV-I' and 'CAS 500-I' and the space launch vehicle "KSLV-II" under development. Recently, Korea and U.S. agreed to end bilateral missile guidelines. Therefore it is expected that development of Korean space industry will be accelerated due to the disappearance of the constraining factors for the development of space launch vehicles. Accordingly, this study examined the development and formation of the Korean space industry through the framework of network analysis. Based on this, the effect of structural position in the industrial network as a resource on the performance of Korean space companies was examined. Panel analysis was applied. Through this study, ideas for fostering the domestic space industry and implications for national policy related with building an industrial ecosystem are derived. It contributes to the development of space industry in Korea.

• Journal of Aerospace System Engineering
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• v.15 no.1
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• pp.1-6
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• 2021

U.S contains the best technology, man power, and big investment in space. It considers space as not only a science and technology related area, but also as an industry and national security related area. Korea's space policy focuses on the development of space systems such as satellites and launch vehicles. Space policy systems of the two countries are also different, causing some discrepancy in mutual interest when we talk about cooperation with the U.S. This study introduced U.S space policy framework and compared it with Korea's policy. It is meaningful in that we can find an effective way of cooperation between two countries.