• Journal of the Korean Society of Marine Environment & Safety
• /
• v.14 no.2
• /
• pp.157-162
• /
• 2008

The ship's maneuverability is the important factor to avoid ship's collisions. The ship's maneuverability is usually measured in a deep water, and the turning ability is decreased and the course stability is improved in a shallow water. The variation of the turning ability could cause the risk of collision. In this paper, we proposes application technique of Variable Safe-Guard Ring to consider the shallow water effect and to be simple to estimate the grade of collision risk simultaneously. Through the mathematical simulation, the availability of new method was varified. Therefore this method is expected enough to support a maneuver for collision avoidance.

• Journal of Navigation and Port Research
• /
• v.30 no.10 s.116
• /
• pp.779-785
• /
• 2006

From a point of view of suggesting the method to avoid ship's collision, the speed of ships has to be considered sufficiently according to encounter angle of ships. But the new safe-guard ring of ship's collision avoidance support model in the close quarters is established assuming that the ratio of own ship' speed to a target ship's speed is less than about 1.7. Therefore in this paper, as doing a study concerned with the establishment of safe-guard ring reflected the encounter angle and the speed of ships, we will propose the new model of ship collision avoidance for safe maneuver of ship's collision avoidance.

• Proceedings of the Korean Institute of Industrial Safety Conference
• /
• 1997.11a
• /
• pp.229-234
• /
• 1997

밀폐공간내에서 일어나는 자연대류 열전달은 태양열 집열판, 연료탱크, 원자로의 핵반응로, 초전도 자성체의 냉각 및 건물이나 방의 효율적인 열설계, 화재시의 안전대책등 공업적으로 그 응용성이 매우 광범위하고 다양하게 생활주변에서 흔히 볼 수 있다. 밀폐공간내에 경계층 유동이 존재할 경우, 이 경계층 흐름은 일반적으로 외부유동에서의 경계층 유동과는 달리 코어영역(Core region)에서의 흐름과 서로 밀접한 관계가 있다. (중략)

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2017.07a
• /
• pp.368-371
• /
• 2017

본 논문에서는 GPS기반 가상펜스 시스템과 가상펜스 알고리즘에 대해서 이야기하고, GPS기반 가상펜스 시스템에서 가축의 이탈을 방지하기 위해 설정하는 영역인 경계영역을 설정하기 위한 알고리즘을 제안한다. 그리고 경계영역을 설정하기 위해 필요한 파라미터를 정의하는 실험을 진행하였으며, 속력이 빨라지면 정확도가 증가하는 GPS의 특성에 의해서 가상펜스 시스템에서 가상펜스 디바이스의 안전지역 이탈시 자극이 발생하는 시간이 빨라짐을 확인할 수 있었다.

• Proceedings of the Korean Nuclear Society Conference
• /
• 1995.05b
• /
• pp.805-812
• /
• 1995

산업의 다변화로 인한 에너지의 수요는 증가하고 있고 이에 따라 핵연료의 사용과 사용 후 연료의 안전한 처분은 큰 관심사가 되고 있다. 본 연구에서는 사용후 핵연료의 폐기에 따른 지하동굴의 해석을 비선형 유한요소와 경계요소의 조합에 의하여 수행하였다. 지하 암반의 열 하중에 의한 거동을 해석하기 위해 응력이 집중되는 대상영역은 유한요소로, 무한영역에는 경계요소를 적용하여 해석하였다.

• Journal of Navigation and Port Research
• /
• v.31 no.5 s.121
• /
• pp.333-338
• /
• 2007

In this paper, we have studied the ship collision avoidance support on the basis of 'Ship Collision Avoidance Model considered a Speed' for the purpose of the decrease of the human error, caused ship collisions, at sea and the effective support of avoiding ship collisions. The program has been reflected the speed of a target ship, had not been considered in a preceding study. Besides, the program will effectively support a maneuver for a collision avoidance, through the display of a feasible area and the method of a collision avoidance using the own ship's turning characteristic about the action of target ship's course and velocity.

• Proceedings of KOSOMES biannual meeting
• /
• 2017.11a
• /
• pp.215-215
• /
• 2017

• Journal of Korean Society of Disaster and Security
• /
• v.6 no.2
• /
• pp.49-56
• /
• 2013

In this paper, used by the boundary layer wind tunnel test, have conducted a series of wind tunnel experiments, i.e. test the mean velocity profile regarding the surface roughness, turbulence intensity and power spectrum measured by augmentation device. After that, to provide data relevant for the preliminary design step of tall building hazard fluctuating wind loads may be obtained fluctuating pressure coefficients, fluctuating pressure spectrum, autocorrelation coefficients by the boundary layer wind tunnel test. From the results of experiments, this study can be obtained conclusions as follows. 1. We know the fact that the mean velocity profile and the turbulence intensity are well fitted natural wind flow in the boundary layer wind tunnel. 2. The satisfactory agreement of velocity spectrum can be obtained from the compare of fluctuating power spectrum and Von Karman spectrum. 3. We know the fact that the fluctuating pressure spectrums distributed peak at 0.01 Hz-0.1 Hz in the windward surfaces and at 0.1 Hz in the leeward surfaces. 4. We know the fact that the autocorrelation coefficients distributed stationary random processes with application time of hazard fluctuating wind loads.

• Journal of Platform Technology
• /
• v.9 no.2
• /
• pp.46-54
• /
• 2021

Recently, interest in the safety of Self-driving has been increasing. Self-driving have been studied and developed by many universities, research centers, car companies, and companies of other industries around the world since the middle 1980s. In this study, we propose the automatic extraction method of the threatening obstacle on the Road for the Self-driving. A threatening obstacle is defined in this study as a comparatively large object at center of the image. First of all, an input image and its decreased resolution images are segmented. Segmented areas are classified as the outer or the inner area. The outer area is adjacent to boundaries of the image and the other is not. Each area is merged with its neighbors when adjacent areas are included by a same area in the decreased resolution image. The Obstacle area and Non Obstacle area are selected from the inner area and outer area respectively. Obstacle areas are the representative areas for the obstacle and are selected by using the information about the area size and location. The Obstacle area and Non Obstacle area consist of the threatening obstacle on the road. Through experiments, we expect that the proposed method will be able to reduce accidents and casualties in Self-driving.

• Geophysics and Geophysical Exploration
• /
• v.14 no.1
• /
• pp.50-57
• /
• 2011

For effective and accurate prediction of overpressure in the Efomeh field, located in the Niger delta basin of Nigeria, integrated seismic and borehole analyses were undertaken. Normal and abnormal pore pressure zones were delineated based on the principle of normal and deviation from normal velocity trends. The transition between the two trends signifies the top of overpressure. The overpressure tops were picked at regular intervals from seismic data using interval velocities obtained by applying Dix's approximation. The accuracy of the predicted overpressure zone was confirmed from the sonic velocity data of the Efomeh 01 well. The variation to the depth of overpressure between the predicted and observed values was less than 10mat the Efomeh 01 well location, with confidence of over 99 per cent. The depth map generated shows that the depth distribution to the top of the overpressure zone of the Efomeh field falls within the sub-sea depth range of 2655${\pm}$2m (2550 ms) to 3720${\pm}$2m (2900 ms). This depth conforms to thick marine shales using the Efomeh 01 composite log. The lower part of the Agbada Formation within the Efomeh field is overpressured and the depth of the top of the overpressure does not follow any time-stratigraphic boundary across the field. Prediction of the top of the overpressure zone within the Efomeh field for potential wells that will total depth beyond 2440m sub-sea is very important for safer drilling practice as well as the prevention of lost circulation.