• Journal of Navigation and Port Research
• /
• v.37 no.4
• /
• pp.337-343
• /
• 2013

To ensure the safety for vessels anchored in stormy weather, duty officer and VTS operator have to frequently check whether their anchors are dragging. To judge dragging of the anchored vessel, it is important for VTS operator to recognize the turning circle and its center of the anchored vessel. The judgement for the anchored vessel dragging can be made by using Radar and AIS. If it is available, CCTV or eye-sighting can be used to know the center of turing circle. However, the VTS system collects individual ship's dynamic information from AIS and ARPA radar and monitors of the anchored vessels, it is difficult for VTS operator not only to get the detailed status information of the vessels, but also to know the center of turning circle. In this study, we propose an efficient algorithm to estimate the center of turning circle of anchored vessel by using the ship's heading and position data, which were from AIS. To verify the effectiveness of the proposed algorithm, the experimental study was made for the anchored vessel under real environments.

• Journal of Navigation and Port Research
• /
• v.27 no.5
• /
• pp.465-471
• /
• 2003

A coastwise chemical tanker sailing at full speed has capsized during turning in calm water. In the previous paper, we investigated the reasons of the accident by demonstrating the proper correction for the free surface effect of the liquid cargo and the bow-sinkage effect. In this paper, we also carry out model experiments of a transverse pressure under the seawater and an outward heel moment according to the heel angle and rudder angle, on the basis of radius of turning circle, ship's speed and drift angle of model ship occurring in turning. It is also shown that the flooding of seawater onto the deck occurring in turning generated a significant outward heel moment and increased the vertical distance between the center of gravity of the ship and the center of lateral water drag.

• Journal of Information Management
• /
• v.8 no.6
• /
• pp.175-177
• /
• 1975

• 프린팅코리아
• /
• s.49
• /
• pp.80-85
• /
• 2006

각 거래처 영업 중심으로 전개되던 제지업계의 마케팅 전략이 최근 브랜드 차별화를 통한 ‘브랜드 마케팅’으로 급격히 선회하고 있다. 이러한 ‘브랜드 마케팅’의 강화는 새로운 패러다임을 요구받는 제지업계의 변화를 보여주는 구체적인 징표가 되며 중간재 성격이 강한 종이가 소비재 개념으로 확대될 수 있는 중요한 기회를 제공하고 있다.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.22 no.6
• /
• pp.56-63
• /
• 2018

In low swirl combustors the flame is lifted above the nozzle to achieve balance between the flame speed and velocity field at the exit of the nozzle. Characterization of the flame liftoff height is important because it affects the stability of the combustor and degradation of the nozzle material. In experiments, a counter-intuitive trend of flame liftoff heights with respect to inlet velocities was observed. To elucidate the complicated flow field in a low swirl combustor having swirl vanes and a turbulence generator, a series of numerical simulations of non-reacting flows was conducted by varying the inlet velocity. The flow structures at the exit of the nozzle with respect to the inlet velocities are investigated to support the observation in the experiments.

• Journal of Advanced Marine Engineering and Technology
• /
• v.37 no.6
• /
• pp.623-630
• /
• 2013

This study was to evaluate hydrodynamic performance evaluation between an abroad product, a developed inflatable kayak and new developed kayaks. In order to test, inclining and turning trial test were carried out in the Ocean engineering Basin. Also, resistance test was carried out using a reduced scale model in the circulating water channel. In conclusion, stability of KONA was evaluated was the most greatest, the coefficient of resistance and center of gravity from RD-FK-12 were considerable, and turning performance of RD-FK-11 was greater than this of KONA and RD-FK-12.

• 주택과사람들
• /
• s.210
• /
• pp.68-71
• /
• 2007

강남 재건축 단지의 분의기가 심상치 않다. 최근에는 올 봄보다 소폭 오른 가격에 거래되는 등 반등 기세를 보이고 있다. 이는 수요자들이 내년 정권 교체 가능성에 무게 중심을 두면서 재건축 규제가 다소 완화될 거라는 기대 심리가 높아졌고, 강남권주택 공급의 저조에 따른 매수 수요의 움직임, 리모델링으로 선회하고 있는 재건축 단지의 시세 상승 영향이 컸기 때문이다. 내년 다선을 앞두고 강남권 재건축 시장의 최근 변화에 대해 살펴보았다.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.1
• /
• pp.511-519
• /
• 2021

Slewing bearing is applied to the transmission of rotational power of the body and turret in a special vehicle for anti-aircraft weapons that overcomes the enemy flight system approaching at low altitudes with rapid response fire. When the turret load and impact load generated when shooting are combined in performing the combat mission of a special vehicle, structural stability must be secured to achieve a successful function. Among the components of the slewing bearing, the stability of the components against the complex loads acting by the turret drive and shooting was evaluated by considering the shape and material characteristics of the ring-gear, roller, and wire-race. As a research method for stability evaluation, based on engineering theory, the strength characteristics of the components were examined by numerical calculations. Finite element analysis was performed on components using the ANSYS analysis program. The results of theoretical analysis and the results of finite element analysis were very similar. A structural stability evaluation for the slewing bearing, which was performed mainly on the analysis, confirmed that the design strength of the slewing bearing determined in the preliminary design in the early stage of localization development was sufficient.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.36 no.3
• /
• pp.258-263
• /
• 2008

Performance of injector equiped with screw type swirler which is suitable for supersonic cruise engine combustor was investigated using theoretical, numerical, and experimental methods. Based on discharge coefficient and spray angle which represent the performance of injectors, the geometrical parameters which affect these performance parameters were defined, control group injectors were designed, and variation of performance parameters according to the geometrical parameters were examined. Within the defined range, measured value of performance of injectors was smaller than result of theoretical prediction, and prediction result from numerical simulation using VOF method agreed with the result of experiments very well. The viscous barrier was not observed, and minimum discharge coefficient and maximum spray angle, 0.05 and 104 respectively, was obtained for this type of injector.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2014.10a
• /
• pp.149-150
• /
• 2014

VLOC와 ULOC를 포함한 케이프급 광탄선과 LNG 운반선 등 수백차례 이상 축적된 거대형 선박조종의 현장겸험을 정리하여 유사한 선박의 조종이나 학술적인 연구에 도움을 주고자 하는 것이 본 연구의 목적이다.