• Proceedings of the KSME Conference
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• 2000.11b
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• pp.668-673
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• 2000

Spud angle( ${\alpha}$ ) and fuel injection angle ( ${\beta}$ ) have strong influence on spud type gas burner combustion. A wide range of flame stability is shown at ${\alpha}=60^{\circ}$, but at ${\alpha}=30^{\circ}$ is narrow. Optimum condition of flame stability swirl angle( ${\gamma}$ ) is $40^{\circ}$. At condition of ${\alpha}=30^{\circ}$ flame shape is relatively narrow and long, on the other hand, at ${\alpha}=60^{\circ}$ flame is wide and short. Regardless of spud angle, maximum flame temperature shows in the range of Z=200mm and R=0mm. Flame temperature, on the whole, is high at ${\alpha}=45^{\circ}$. At ${\alpha}=45^{\circ}$, NOx emission is higher than other conditions that may be concerned with flame temperature. At ${\beta}=60^{\circ}$ and ${\gamma}=40^{\circ}$, NOx emission is reduced due to fuel injection angle.

• Journal of the Korean Institute of Navigation
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• v.15 no.4
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• pp.59-78
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• 1991

항만 설계에 영향을 미치는 네가지 중요요인인 선박요인, 인간요인, 환경요인 및 항로표지요인들이 실제 항만 및 수로의 설계에 미치는 구체적인 영향들을 각 요인별로 분석하였다. 아울러 항만 및 수로 설계요소인 수심, 항로의 폭, 항로의 배치, 선회수역의 크기 및 부두의 배치 문제에 대한 분석을 기하였다. 그리고, 항만 및 수로의 설계 문제에 관한 최근의 연구결과들과 각국의 설계 Guideline들을 수집하여 특히, 항로의 폭, 항로의 배치 그리고 선회수역의 크기에 대해 그 내용을 비교하고 분석하였다. 이들 연구 결과들과 항만 설계기준들은 연구 방법과 설계 기준을 마련한 기구들에 따라 그 내용의 차이가 있음이 확인되었다. 따라서 이들 기준들은 항만 설계를 위한 1차 계획 수립시에만 활용되고 세부적인 설계는 1차 설계 후 항만 설계 시뮬레이션 기법을 통한 검정을 거쳐야만 안전한 항만의 설계 및 개발이 이루어질 수 있다는 것이 확인되었다.

• Proceedings of the KSME Conference
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• 2000.11b
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• pp.692-697
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• 2000

Recently, Flat flame burners are hilighted in high-load burners. Our study contains flow field analysis of a flat flame burner. In this paper, We analyzed the direction and magnitude of the velocity in a round tile type burner with swirl angles, $10^{\circ},\;30^{\circ},\;50^{\circ}$. In the case of swirl angle $10^{\circ}$, because axial momentum is larger than radial momentum, Recirculation region was weakly developed. In the case of swirl angle $50^{\circ}$, Flow in front of the tile is distributed for radial direction. And Recirculation region is large. So, We expect that the radiation can be transmitted from tiles and the recirculation region may cause $NO_x$ reduction.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.11a
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• pp.1026-1027
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• 2017

안전 대응 훈련 기술은 플랜트와 같은 위험한 작업현장에서 조업자 또는 초기 대응자가 예상치 못한 사고에 대해 능동적이고 신속한 대처가 가능하도록 계획적인 사전 대응 훈련을 수행할 수 있는 시스템 기술이다. 훈련 시나리오의 가장 기본적이며 빈번하나 과업은 특정 지점으로의 이동과 원하는 시설물을 탐색하는 네비게이션 임무라 할 수 있다. 본 연구에서는 작은 크기를 가지는 단방향 트레드밀의 장점과 선회 보행이 가능한 전방향 트레드밀의 장점을 일부 결합하여, 작은 각도 범위의 좌우 선회 이동을 지원할 수 있는 트레드밀 인터페이스의 제어를 위한 기술개발 과정과 결과를 소개 하고자 한다.

• Journal of Energy Engineering
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• v.4 no.1
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• pp.23-30
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• 1995

분류층 가스화기 설계를 위한 일차연구로서 가스화기 종횡비, 주입方法, 선회강도 및 주입속도 등에 따른 비반응 난류장 특성을 수치해석적 방법에 의해 파악하였다. 수치해석은 검사체적에 기초한 Patankar의 유한차분방법을 이용하였으며 압력과 속도의 연계문제는 SIMPLEC 알고리즘을, 레이놀즈 전단력은 K- 난류모델을 사용하였다. 입자궤적 계산은 공기역학적 향력만을 고려하였으며 비선형적인 공기저항력에 의한 난류변동상관모델은 고려치 않았다. 이차공기 주입방법(parallell injection과 nonparallel 3$0^{\circ}C$ imjection)에 따른 수치해석을 수행하여 Ar tracer의 질량분율 및 기타 속도에 대한 實驗資料와 비교하여 만족할 만한 結果를 얻었다. 나아가서 假想的인 가스화기 모델을 대상으로 가스화기의 종횡비, 선회강도, 주입속도 및 주입각 등에 따른 와류 形成 위치 등을 포함한 유동장 특성 및 입도에 따른 궤적분석을 시도하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2018.10a
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• pp.873-874
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• 2018

화학공정 플랜트와 같이 위험한 작업현장에서 현장 조업자 또는 초기 대응자가 능동적이고 신속한 대처가 가능한 가상현실기반 안전대응 훈련기술에 있어, 원하는 시설물을 가상으로 탐색할 수 있는 네비게이션 임무를 통한 체감공간인식 및 임무수행기술이 중요하다. 본 연구에서는 작은 크기를 가지는 단방향 트레드밀의 장점과 선회 보행이 가능한 전방향 트레드밀의 장점을 일부 결합하여, 작은 각도 범위의 좌우 선회 이동을 지원할 수 있는 트레드밀 인터페이스 시제품을 이용한 사용자 모션인식 및 통합제어 기술개발 과정과 결과를 소개 하고자 한다.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.12 no.4
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• pp.209-215
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• 1979

The manoeuvrabilities of a ship are decided by the values of her manoeuvring indices. The manoeuvring indices consist of two kinds: indices K and T. The former decides a ship's turning ability and the latter, the length of time delay to a steady turning motion after her rudder has finished the turn of an ordered angle. In this paper, the author figured out the values of the manoeuvring indices of the m. s. 'SAEBADA' (GT: 2,275,7 ton), the training ship of tile National Fisheries University of Busan through her Z test and analyzed these values and the other data which were obtained from her Z test to study her manoeuvrabilities. The results of]tamed are summarized as follows: 1. The manoeuvring indices K' of the m. s. 'SAEBADA' were $1.052(at\;10{\circ}\;Z\;test)\;0.925(at\;20{\circ}\;Z\;test)\;and\;0.877(at\;30{\circ}\;Z\;test)$. Her manoeuvring indices $0.815(at\;10{\circ}\;Z\;test)\;0.502(at\;20{\circ}\;Z\;test)\;and\;0.441(at\;30{\circ}\;Z\;test)$. Her above calculated values K', T' showed that her obeying ability to the turn of her rudder was more increased when her rudder was used to large angle than to small angle, but on the other hand in this case her turning ability was slightly reduced. 2. As it appeared that the calculated K'-values of the m.s. 'SAEBADA' were slightly smaller than the standard K'-values of the fishing boats similar in length, and her overshoot angles at her Z test were greater than other general ships, her turning ability was found to t]e slightly lower. 3. When the m. s. 'SAEBADA' took a turn at her $10^{\circ}\;Z$ test, running distance was about 8.6 times her own length and didn't exceed the standard manoeuvrability distance, 5 to 11 times general ships' own length, therefore she was considered to have a good manoeuvrability synthetically.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.64-70
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• 2018

Rollover is a major concern for vehicles with a higher center of gravity and for improving driving performance. This study investigates a tilting system to prevent rollover, which was successfully implemented for high-speed trains. It may be useful to apply the concept of the tilting system to a large truck such as a trailer. Even a small adjustment in the tilting angle can improve the driving stability during a steep turn. The equation of motion was derived from a dynamic model of the trailer with the tilting system. The balance of the centrifugal force and normal force determines the rollover critical speed for a given radius of the turn and load. To obtain a more conservative criterion, the rollover critical state was defined as the instant when any side wheel loses contact with the road. To actuate the tilting system, the optimal tilting angle must be calculated from the steering angle and the vehicle speed. Using a simplified model of a large truck, the effects of the tilting angle and load on the rollover critical speed were investigated.

• Journal of Navigation and Port Research
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• v.45 no.6
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• pp.284-297
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• 2021

A simple kinematic model for the prediction of ship manoeuvres based on trial data is proposed in this study. The model consists of first order differential equations in surge, sway, and yaw directions which simulate the time series of each velocity component. Actually instead of sea trial data, dynamic model simulations are conducted with randomly varied control inputs such as propeller revolution rates and rudder angles. Based on learning of control inputs and velocity outputs of dynamic model simulations in sufficient time, kinematic model coefficients are optimized so that the kinematic model can be approximately reproduce the velocity outputs of dynamic model simulations with arbitrary control inputs. The resultant kinematic model is verified with new dynamic simulation sets.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1731-1737
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• 2007

This paper considers subway routing problem. Given a schedule of train to be routed by a railway stock, the routing problem determines a sequence of trains while satisfying turnaround time and maintenance restrictions. Generally, the solution of routing problem is generated from set partition formulation solved by column generation method, a typical integer programming approach for train-set. However, we find the characteristics of metropolitan subway which has a simple rail network, a few end stations and 13 departure-arrival patterns. We reflect a turn-around constraint due to spatial limitations has no existence in conventional railroad. Our objective is to minimize the number of daily train-sets. In this paper, we develop two basic techniques that solve the subway routing problem in a reasonable time. In first stage, we formulate the routing problem as a Min-cost-flow problem. Then, in the second stage, we attempt to normalize the distance covered to each routes and reduce the travel distance using our heuristic approach. Applied to the current daily timetable, we could find the subway routings, which is an approximately 14% improvement on the number of train-sets reducing 15% of maximum traveling distance and 8% of the standard deviation.