• 대한기계학회논문집B
• /
• 제32권8호
• /
• pp.604-611
• /
• 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.

• 한국측량학회지
• /
• 제39권5호
• /
• pp.265-278
• /
• 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.

• 대한토목학회논문집
• /
• 제42권1호
• /
• pp.45-56
• /
• 2022

최근 수원시 내 공유자전거 도입 및 이용이 활성화되고 있다. 이에 따라 자전거 도로 인프라가 확충되어야 함에도 불구하고, 그렇지 못한 상황이다. 따라서, 본 연구에서는 수원시 자전거 전용차로 도입 방안을 제시하고자 하였다. 이를 위해 모바이크에서 제공한 2018년 9월 10일~16일 기간 내 공유자전거 이용 데이터와 교통유발시설 현황 데이터를 기반으로 입지분석을 수행하였다. 분석결과를 활용하여 수원시 내 자전거 전용차로 도입 적정 구간을 선정하였다. 최종적으로 수원시 내 자전거 전용차로 우선 도입구간으로 총 2개, 5.6 km 구간을 선정하였다. 해당 구간들은 기존 자전거 도로 인프라 또는 교통유발시설과의 연계가 용이하고, 기운영중인 자전거 도로를 활용하여 설치가 용이하다는 장점이 있으나, 기존 도로공간 점유로 인한 교통정체가 발생하는 단점이 있음을 알 수 있었다. 본 연구를 통해 수원시 내 자전거 전용차로 도입 활성화 및 인프라 정비 사업 확대, 공유자전거 및 공유 PM 등 공유형 교통수단 이용 활성화, 관내 지속가능 도시교통체계가 구현되길 기대한다.

• 국제학술발표논문집
• /
• The 8th International Conference on Construction Engineering and Project Management
• /
• pp.510-519
• /
• 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.

• 한국항행학회논문지
• /
• 제27권5호
• /
• pp.561-567
• /
• 2023

본 연구에서는 유인기 회랑에 적용되는 충돌 위험 모델을 활용하여 UAM (Urban Air Mobility) 회랑의 충돌 위험을 분석하였다. K-UAM 로드맵과 운용개념서에 따르면 UAM은 기존 유인기 운항과 유사하게 지정된 항로를 비행하는 형태를 가지며 출발지와 도착지를 왕복하는 두 가지의 노선으로 운행될 것으로 예상된다. 국내 유인기 노선 중 김포공항-제주공항 간 유인기 운행이 이와 유사하며 두 개의 노선 간 횡 방향 분리간격을 가진 평행항로 형태를 띤다. 본 연구에서는 이와 유사한 형태의 UAM 회랑에 대해 유인기 평행 항로 충돌 위험 분석에 활용되는 충돌 위험 모델을 활용하여 횡 방향 분리간격에 따른 UAM 회랑의 충돌 위험을 분석하였다. 이를 바탕으로 최종적으로 K-UAM 실증 노선을 고려하여 한강 폭 내에 몇 개의 평행 항로가 설치될 수 있는지 분석하였다.

• 동굴
• /
• 제93호
• /
• pp.43-51
• /
• 2009

고수동굴의 관람대상물의 분포는 이층 구조로 되어 있어 입체적 분포를 보인다. 그러나 관람루트는 정해진 루트를 이동하기 때문에 그래프상의 목(tree)형 형태를 갖는다. 이러한 관람 포인트와 관람대상물의 관계를 통한 관람루트의 특성을 네트워크 분석기법을 이용하여 분석하였다. 타동굴과의 비교 분석이 아니므로 수치적 해석에 한계가 있었으나 차후 유사한 동굴간의 관람루트를 비교 분석하거나 관람방식에서 생기는 문제점을 파악하는 기초자료로 제공 될 수 있다.

• 한국경영과학회지
• /
• 제30권3호
• /
• pp.41-54
• /
• 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.

• 한국항공운항학회지
• /
• 제25권3호
• /
• pp.51-60
• /
• 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.

• 한국농공학회:학술대회논문집
• /
• 한국농공학회 2000년도 학술발표회 발표논문집
• /
• pp.233-238
• /
• 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.

• 한국농촌건축학회논문집
• /
• 제7권3호
• /
• pp.93-100
• /
• 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.