• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.8
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• pp.604-611
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• 2008

Detailed analysis of NO formation routes and its contributions with strain rate in hydrogen/air flames were numerically investigated. LiG detailed reaction mechanism has been used for calculation, which is compared with experimental data in literature. It shows good agreement with experiment for both temperature and NO mole fraction. Three routes have been found important for NO formation in hydrogen flames. These are the Thermal route, NNH route and $N_2O$ route. Strain rate were varied to discuss the $EI_{NO}$ reduction trend in hydrogen nonpremixed flames, which are analyzed by each NO formation routes. As a result, as the strain rate increase, $EI_{NO}$ decrease sharply until strain rate $100s^{-1}$ and decrease slowly until strain rate $310s^{-1}$ again, after that $EI_{NO}$ keeps nearly constant. It can be identified that $EI_{NO}$ trend with the strain rate is well explained by a combination of variation of production rate of above Thermal, NNH and $N_2O$ route. Also result of Thermal-Mech. that includes only thermal NO reaction is compared with those of Full-Mech. As a result, It can be identified that there was difference between the two results of calculation. It is attributed to result that Thermal-mech did not consider contributions of NNH and $N_2O$ route. From these result, we can conclude that NOx emission characteristics of hydrogen nonpremixed flames should consider contributions of above three routes simultaneously.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.5
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• pp.265-278
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• 2021

When a dangerous event arises for people inside a building and an immediate evacuation is required, it is important that suitable routes have been previously defined. These situations can happen especially when buildings are crowded, making the occupants have a very high vulnerability and can be trapped if they do not evacuate quickly and safely. However, in most cases, routes are considered based just on their proximity or short distance to the exit areas, and evacuation simulations that include more variables are not performed. This work aims to propose a methodology for building's indoor evacuation activities under the premise of processing simulation scenarios in multi-agent environments. In the methodology, importance indexes of simplified and validated geometry data from a BIM (Building Information Modeling) are considered as heuristic input data in a proposed algorithm. The algorithm is based on AP-Theta^* pathfinding and collision avoidance machine learning techniques. It also includes conditioning variables such as the number of people, speed of movement as well as reaction ability of the agents that influence the evacuation times. Moreover, collision avoidance is applied between people or with objects along the route. The simulations using the proposed algorithm are tested in NetLogo for diverse scenarios, showing feasible evacuation routes and calculating evacuation times in a multi-agent environment. The experimental results are obtained by applying the method in a study case and demonstrate the level of effectiveness of the algorithm, and the influence of the conditioning variables analyzed together when performing safe evacuation routes.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.1
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• pp.45-56
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• 2022

Recently, bicycle sharing system is introduced and the usage of shared bicycles is increasing in Suwon city. Despite the need to expand the bicycle road infrastructure, this is not the case. Therefore, this research attempts to propose a method for bicycle lane installation in Suwon city. For this, this research conducted location analysis based on the shared bicycle usage data and trip inducing facility data. Using location analysis results, appropriate routes for bicycle lanes are selected. As a result, two routes are selected. These routes have advantages that it is easy to connect with the existing bicycle roads or traffic inducing facilities and to install using the existing bicycle roads. However, these routes also have disadvantage that traffic congestion may occur due to the occupancy of the existing road space. It is expected that this research may contribute to expansion and maintenance of bicycle lane infrastructure, the bicycle and PM sharing service usage, implementation of sustainable urban transportation systems in Suwon city.

• International conference on construction engineering and project management
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• 2020.12a
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• pp.510-519
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• 2020

Within an intelligent automated cyber-physical system, the realization of the autonomous mechanism for data collection, data integration, and data analysis plays a critical role in the design, development, operation, and maintenance of such a system. This construct is particularly vital for fault-tolerant route-finding systems that rely on the imprecise GPS location of the vehicles to properly operate, timely plan, and continuously produce informative feedback to the user. More essentially, the integration of digital twins with cyber-physical route-finding systems has been overlooked in intelligent transportation services with the capacity to construct the network routes solely from the locations of the operating vehicles. To address this limitation, the present study proposes a conceptual architecture that employs digital twin to autonomously maintain, update, and manage intelligent transportation systems. This virtual management simulation can improve the accuracy of time-of-arrival prediction based on auto-generated routes on which the vehicle's real-time location is mapped. To that end, first, an intelligent transportation system was developed based on two primary mechanisms: 1) an automated route finding process in which predictive data-driven models (i.e., regularized least-squares regression) can elicit the geometry and direction of the routes of the transportation network from the cloud of geotagged data points of the operating vehicles and 2) an intelligent mapping process capable of accurately locating the vehicles on the map whereby their arrival times to any point on the route can be estimated. Afterward, the digital representations of the physical entities (i.e., vehicles and routes) were simulated based on the auto-generated routes and the vehicles' locations in near-real-time. Finally, the feasibility and usability of the presented conceptual framework were evaluated through the comparison between the primary characteristics of the physical entities with their digital representations. The proposed architecture can be used by the vehicle-tracking applications dependent on geotagged data for digital mapping and location tracking of vehicles under a systematic comparison and simulation cyber-physical system.

• Journal of Advanced Navigation Technology
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• v.27 no.5
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• pp.561-567
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• 2023

In this study, the collision risk of the UAM (Urban Air Mobility) corridor was analyzed using a collision risk model applied to the manned aircraft corridor. According to the K-UAM roadmap and operating concept, UAM is expected to fly on a designated route similar to existing manned aircraft operations and operate on two routes, traveling back and forth between the departure point and the destination point. Among domestic manned aircraft routes, the manned aircraft operation between Gimpo Airport and Jeju Airport is similar to this and takes the form of a parallel route with a lateral separation distance between the two routes. In this study, we analyzed the collision risk of the UAM corridor according to the lateral separation distance using a collision risk model used to analyze the collision risk of manned aircraft parallel routes for a similar type of UAM corridor. Based on this, we finally analyzed how many parallel routes could be installed within the width of the Han River, considering the K-UAM demonstration route.

• Journal of the Speleological Society of Korea
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• no.93
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• pp.43-51
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• 2009

Due to the tour route of Gosu cave's designated route, it has a specific shape of a tree. There are some limitations because of there being no comparable analysis to other caves. However, it will be provided as basic data to do the comparable analysis with similar caves' tour routes, and to understand some problems according to the viewing route.

• Journal of the Korean Operations Research and Management Science Society
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• v.30 no.3
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• pp.41-54
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• 2005

In this paper, we consider a multi-objective machine cell formation problem. This problem Is characterized as determining part route families and machine cells such that total sum of inter-ceil part movements and maximum machine workload imbalance are simultaneously minimized. Together with the objective function, alternative part routes and the machine sequences of part routes are considered In grouping Part route families. Due to the complexity of the problem, a two-phase heuristic algorithm is proposed. And we developed an n-stage look-ahead heuristic algorithm that generalizes the roll-out algorithm. Computational experiments were conducted to verify the performance of the algorithm.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.25 no.3
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• pp.51-60
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• 2017

Estimation of the taxi-out and taxi-in times of aircraft on a airport surface is one of the essential features of Departure Manager (DMAN). Especially for an airport with multiple runways and large ramp areas, estimation of the taxi-out and taxi-in times are mainly dependent on the taxi routes on airport surface. This paper described the method of automatic extraction of the the taxi routes using the ASDE track data and the Dijkstra algorithm based on the node-link model of a airport surface movements. In addition, we analyzed the ground operation status of Incheon International Airport using the extracted taxi routes.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.233-238
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• 2000

Many theories and researches about agricultural products transportation were proposed and introduced until now. These studies have insufficient consideration about factors like region of imported agricultural products and the different speed of each road. In this study the Optimal Routes Selection Model (ORSEM) included factors that aren't taken into account in past studies and consists of database using Internet. Finally the model was developed through advanced marketing potential function and optimization method. The ORSEM focalizes on transport network organization. This model was applied to physical distribution of agricultural products in South Korea and found optimum routes of agricultural products.

• Journal of the Korean Institute of Rural Architecture
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• v.7 no.3
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• pp.93-100
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• 2005

The purpose of this study is to investigate specific crowding areas resulted from diverse physical factors of multi-plex theaters in a fire evacuation, and more accurately predict the evacuation route of people. To achieve these purpose, the architectural characteristics of three multi-plex theaters in Jinju have been chosen, and the evacuation experiments through the computer simulation called Simulex were carried out for each on the these theaters. The conclusions from this study are as follows: (1) Crowding usually happens cross areas between theater inside and corridors, and Crowding rate depending on the number of cross areas. (2) It is necessary to design the escape routes being employed ordinary times. And the egress routes planning should be integrated into space programming at the early stage of building design.