• 대한조선학회논문집
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• 제41권2호
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• pp.98-105
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• 2004

This study focuses on an analytical approach to calculate four crane lifting forces for heavy ship hull blocks considering elongations of lilting slings. Four-crane-lifting is a redundant problem. During lifting procedures, in addition to the force and moment equilibrium equations, a compatibility condition is introduced to determine 4 unknown lifting forces. For verification of the method, a ship hull block with field measurements data is analyzed and the result shows that the information obtained by current method could be useful to engineers to conduct lifting work at shipyards.

• 한국해양공학회지
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• 제14권1호
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• pp.17-22
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• 2000

This study focuses on a simple analytical approach to calculate crane lifting forces for a sunken ship. The method takes into account the relation of lifting forces acting in wire rope slings to the inclination of the vessel including the effect of lug positions. The importance of the sunken ship salvage is explained from the statistics of ship casualties during last 15 years. Euler angles are introduced to represent the inclination of a sunken ship in developing the static force and moment equations,. Three dimensional examples with one redundant degree of freedom for a GT1500 oil tanker are analyzed and the results show that the information obtained by the method could be useful to salvors to conduct salvage work.

• Journal of Advanced Marine Engineering and Technology
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• 제24권4호
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• pp.502-508
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• 2000

The amount of container freight is continuously increasing recently, but freight congestion problem frequently occurs at ports due to low efficiency of container crane in transportation and cargo handling. In this paper, a method for designing a fuzzy controller of the container crane system is presented. In this scheme a mathematical model for the system is obtained in state space representation. The response of the proposed fuzzy controller is compared with that of the optimal controller at the same condition. Through the simulation results, the performance of the fuzzy controller was observed better than that of optimal controller in respect of reference change, disturbances and parameter change. The fuzzy controller was also more stable and robust than the optimal controller.

• Journal of Advanced Marine Engineering and Technology
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• 제32권4호
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• pp.624-629
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• 2008

This paper presents a scheme for designing a state observer for container cranes. If the system is completely observable with a given set of outputs, then it is possible to determine the states that are not directly measured. We consider the reduced-order states observer with only trolley position detection and with trolley position and container angle detection. The gain matrix of the each state observer is adjusted using a RCGAs. A set of simulation works is carried out to demonstrate the effectiveness of the proposed scheme.

• 한국안전학회지
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• 제8권4호
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• pp.65-72
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• 1993

This study is conducted for both examination of a possiblity of danger and investigation of operational condition of selected 120 companies, to establish the safety standard of workplace hazards.

• 동력기계공학회지
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• 제7권4호
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• pp.74-81
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• 2003

An LQ controller design method is proposed for effective anti-sway control of boom type crane in this paper. It is important for high productivity that the sway of a load is controlled as fast as possible when the trolley arrives to the destination with maximum velocity. To prove the effectiveness of the proposed LQ controller. simulations and experiments using the boom type crane as experimental device is carried out. Tracking performance for a step type reference and robustness for the change of working environment such as the change of load weight and parameters produced by a wire rope and disturbance by the wind arc proved by the experiment. It will be examined that boom type crane can be applied to industrial fields through experiment in this paper.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 B
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• pp.609-611
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• 1999

산업현장의 제어기들은 센서들로부터 수집된 다양한 형태의 신호들을 처리한다. 이 신호들은 고정된 값을 가지지 않고 물리적으로 변화하는 특성을 가진다. 이와 같이 변화하는 값을 처리하는 방법으로 다양한 형태의 연구가 진행되고 있고, 그 한 분야로 퍼지(Fuzzy)이론을 바탕으로 한 퍼지 제어 시스템에 대한 연구가 활발하게 진행되고 있다. Fuzzy PLC 시스템은 현재 초기단계 형태로 개발되어 사용되고 있으며 그 응용 방법도 조금씩 보급되고 있는 실정이다. 본 논문은 변화하는 값들에 대해 간결하고 적절한 제어를 수행 할 수 있는 기 개발된 Fuzzy PLC 시스템을 이용한 플랜트 제어에 대한 연구이다. 크레인(Crane) 제어용으로 사용한 Fuzzy PLC 시스템은 Moeller사의 FT4-400-MM2 PLC 모듈이다. 본 시스템을 이용하여 대상 플랜트인 크레인을 제어하는 퍼지 함수 로직을 개발하고, 입 출력 제어 프로그램 기법에 대하여 연구한다. 또한 퍼지 제어 시스템을 이용한 퍼지 제어 기법을 개발하는 과정에 대하여 소개한다. 결론적으로 Fuzzy PLC System 개발 및 응용 모델로서 제안하고자 한다.

• 한국해양공학회지
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• 제17권3호
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• pp.33-38
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• 2003

This study focuses on an analytical approach to calculate crane-lifting forces for a sunken ship, with consideration to elongation of crane ropes. The method takes into account the relation of lifting forces acting in wire rope slings to the inclination of the ship's hull, including the effect of lug positions. For lifting analysis, the Euler angles are defined to represent the inclination of a sunken ship in developing the static force and moment equations. An additional compatibility condition is introduced in order to solve an indeterminate lifting analysis problem with 4 cranes. A set of lifting forces along the 4 crane ropes is calculated. A 3-dimensional example of the G/T 1500 oil tanker is analyzed. The results show that the information obtained by the method could be useful to engineers when conducting salvage work.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2003년도 춘계학술대회 논문집
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• pp.179-184
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• 2003

This study focuses on an analytical approach to calculate crane lifting forces for a sunken ship in consideration oj elongation of crane ropes. The method takes into account the relation of lifting forces acting in wire rope slings to the inclination of the ship's hull including the effect of lug positions. For lifting analysis, the Euler angles are defined to represent the inclination of a sunken ship in developing the static force and moment equations. An additional compatability condition is introduced in order to solve an indeterminate lifting analysis problem with 4 cranes and a set of lifting forces along the 4 crane ropes is calculated. A 3-dimensional example of the G/T 1500 oil tanker is analyzed and the results show that the information obtained by the method could be useful to engineers to conduct salvage work.

• 에너지공학
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• 제25권4호
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• pp.207-213
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• 2016

본 연구에서는 화력발전소 터빈 건물의 온도저감 방안을 도출하기 위해 전산유체역학 상용코드인 ANSYS-FLUENT를 이용하여 열유동 해석을 수행하였다. 터빈 건물의 운전층(operating floor)과 탈기기층(deaerator floor)을 검사체적으로 선정하여 모델링을 하였으며 탈기기층에 설치된 기존의 채광창을 활용하여 환기창으로 대체하는 경우에 대해 해석을 수행하였다. 본 연구를 통하여 첫째, 운전층의 온도를 저감하기 위한 방안은 탈기기층의 모든 창문을 열지 않아야 됨을 알았다. 둘째, 탈기기층의 온도를 저감하기 위한 방안으로 탈기기층의 전면부의 창문을 개방하면 탈기기 영역과 크레인 영역은 각각 $1.5^{\circ}C$와 $1.6^{\circ}C$를 저감할 수 있었고, 탈기기 후면부의 창문을 개방하면 탈기기 영역은 $1.4^{\circ}C$, 크레인 영역은 $0.5^{\circ}C$의 온도를 저감할 수 있었다. 따라서 고온의 탈기기층 전체 영역의 온도를 저감하기 위해서는 탈기기층 전면부의 창문을 개방하는 것이 유리할 것으로 판단된다.