• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.387-392
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• 2006

In the environment where AGVs(Automated Guided Vehicles) operate concurrently in limited space, collisions. deadlocks, and livelocks which have negative effect on the productivity of AGVs occure more frequently. The accelerated motion of an AGV is also the factor that make the AGV routing more difficult because the accelerated motion makes it difficult to estimate the vehicle's exact travel time. In this study, we propose methods of avoiding collisions, deadlocks, and livelocks using OAR(Occupancy Area Reservation) table, and selecting best route by estimating the travel time of an AGV in accelerated motion. A time-driven simulation validated the effectiveness of the proposed methods.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2003.05a
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• pp.66-72
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• 2003

The paper describes on the implementation of three-dimensional visualization system that is to visualize meaning of the statistical prediction results of marine casualty with easy of understanding. Graphical User Interface(GUI) and Web based Virtual Reality (VR) technology are mainly introduced in the system development. In addition, the time based prediction models of the marine casualty and the risk level are developed to display daily situation. As operating test results of the system, it is known that complicated statistical results can be shown as simple colour in the three-dimensional virtual space.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.271-275
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• 2006

This paper describes the design and realization of full attitude system based on MEMS IMU and GPS carrier phase. The work can be divided into two parts: First, initial heading is determined by using two GPS receivers. And this paper discusses the usage of space geometry conditions to reduce the range of ambiguity search. The method presented in this paper was tested on the static. On the static condition, an accuracy better than 0.06 degrees for heading for 3.48m long baseline has been achieved. Integration of GPS and low cost MEMS IMU are used to realize the real-time heading attitude system. Second, level attitude (pitch and roll) is determined using the method of frequency-velocity for the feedback control. At the same time, the method using the attitude based on MEMS IMU to help determination of the range of ambiguity search is proposed. The results done on the sea show that an alternative means to provide real-time, cost-effective, accurate and reliable attitude information for attitude surveys. Though motivated by a big ships application, the design can be applied to other vehicles.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.77-82
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• 2006

Automatic vessel collision-avoidance systems have been studied in the fields of artificial intelligence and navigation for decades. And to facilitate automatic collision-avoidance decision-making in two-vessel-encounter situation, several expert and fuzzy expert systems have been developed. However, none of them can negotiate with each other as seafarers usually do when they intend to make a more economic overall plan of collision avoidance in the COLREGS-COST-HIGH situations where collision avoidance following the International Regulations for Preventing Collisions at Sea(COLREGS) costs too much. Automatic Identification System(AIS) makes data communication between two vessels possible, and negotiation methods can be used to optimize vessel collision avoidance. In this paper, a negotiation framework is put forward to enable vessels to negotiate to optimize collision avoidance in the COLREGS-COST-HIGH situations at open sea. A vessel vector space is defined and therewith a cost model is put forward to evaluate the cost of collision-avoidance actions. Negotiations between a give-way vessel and a stand-on vessel and between two give-way vessels are considered respectively to reach overall low cost agreements. With the framework proposed in this paper, two vessels involved in a COLREGS-COST-HIGH situation can negotiate with each other to get a more economic overall plan of collision avoidance than that suggested by the traditional collision-avoidance expert systems.

• Journal of Navigation and Port Research
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• v.31 no.1 s.117
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• pp.71-79
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• 2007

This study is intended to investigate the superyacht exterior design style from the viewpoint of marine architectural design. Especially it is focused on the exterior profile design of superyachts. Superyachts are passenger vessels whose hull exceeds 24m. They are a kind of luxurious leisure ships. Marine architectural designer can contribute in the field of exterior and interior design of superyachts. In this study we analyze outboard profile of 32 superyachts and extract key design elements of exterior profiles. Those are sheer line, stem line, bow line, house line and windows.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2009.10a
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• pp.187-188
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• 2009

On this study, the artificial neural network, one of the nonlinear forecasting methods, is compared with ARIMA model through performing a forecast of container traffic. The existing studies have been used the rule of thumb in topology design for network which had a great effect on forecasting performance of the artificial neural network. However, this study applied the genetic algorithm, known as the effectively optimal algorithm in the huge and complex sample space, as the alternative.

• Journal of Satellite, Information and Communications
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• v.7 no.2
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• pp.25-29
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• 2012

In this paper, we implemented LED beam forming communication system controlled by stepping motor. ATMega1284 was used as a MCU of main control board which has two main external IO, one is RS232 for connection with PC, the other is PORT for connection with motor driving board. Stepping motor rotated 360 degree when provided 160 clock and its rotation radius was increased by Archimedian Spiral. So LED can provide its light anywhere in the space and its beam forming was controlled by PC connected with RS232 of main control board. The action of beam forming was verified via actual HW/SW implementation.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.10a
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• pp.125-127
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• 2012

With the progress of electronics and radio communication technology, human enjoys greater freedom in communication. However, EMW (Electro-Magnetic wave) environments have became complicate and more difficult to control. Thus, international organizations, such as the American National Standard Institution (ANSI), Federal Communications Commission (FCC), the Comite Internationale Special des Perturbations Radio electrique (CISPR), etc, have provided standard for controlling the EM wave environments and for the countermeasure of the electromagnetic compatibility (EMC). In this paper, the status of EMW absorber and the goal of smart EMW absorber ifor the future were described. Furthermore, design method of the smart EM wave Absorber with heat radiating function was suggested. The designed smart EM wave Absorber has the absoption ability of more than 5 dB from 2 GHz to 2.45 GHz band, one optimum aperture (hole) size of which was 6 mm, 9 mm in adjacent hole space, and 6.5 mm in thickness, respectivly. Thus, it is repected that these results can be applied to various EMC devices in electronic, communication, and controlling systems.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2009.06a
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• pp.287-288
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• 2009

In this paper we developed positioning algorithm considering distributed energy resource of ocean side by load flow calculation using Newton-Rhapson method.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2009.06a
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• pp.289-290
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• 2009

In this paper we designed the sensor system that is based on the PT, CT and microprocessors for measuring power of distributed energy resource of ocean side.