• Journal of Navigation and Port Research
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• v.28 no.7
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• pp.635-640
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• 2004

In this paper, a tracking algorithm for autonomous navigation of automated guided vehicles (AGVs) operating in container terminals is presented. The developed navigation algorithm takes the form of a federated information filter used to detect other AGVs and avoid obstacles using fused information from multiple sensors. Being equivalent to the Kalman filter (KF) algebraically, the information filter is extended to N-sensor distributed dynamic systems. In multi-sensor environments, the information-based filter is easier to decentralize, initialize, and fuse than a KF-based filter. It is proved that the information state and the information matrix of the suggested filter, which are weighted in terms of an information sharing factor, are equal to those of a centralized information filter under the regular conditions. Numerical examples using Monte Carlo simulation are provided to compare the centralized information filter and the proposed one.

• Journal of Navigation and Port Research
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• v.28 no.7
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• pp.647-651
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• 2004

FPSOs are commonly proposed and used for offshore oil production. Due to the fundamental requirement of FPSOs to remain moored at their location, they are unable to avoid severe weather. FPSOs normally operate head to the weather, and sensitive equipment located near the bow will be susceptible to green water damage. Damage may occur to both equipment and superstructure, with resulting risk to personnel. To initially access green water is allowed by the physical understanding of green water events. In this paper the main focus is put on the physical phenomena of green water accounted for with the tested data in regular waves.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.459-464
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• 2004

In this paper, an autonomous navigation system for autonomous guided vehicles (AGVs) operated in an automated container terminal is designed. The navigation system is based on the sensors detecting the range and bearing. The navigation algorithm used is an interacting multiple model (IMM) algorithm to detect other AGVs and avoid other obstacles using informations obtained from multiple sensors. As models to detect other AGVs (or obstacles), two kinematic models are derived： Constant velocity model for linear motion and constant speed turn model for curvilinear motion. For constant speed turn model, an unscented Kalman filter (UKF) is used because of drawbacks of the extended Kalman filter (EKF) in nonlinear system. The suggested algorithm reduces the root mean squares error for linear motions, while it can rapidly detect possible turning motions.

• Journal of Navigation and Port Research
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• v.33 no.4
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• pp.271-275
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• 2009

A strategic decision making on location selection for product transportation includes many tangible and untangible factors. To choose the best locations is a difficult job in the sense that objectives usually conflict with each other. In this paper, we consider a multi stage multi criteria transshipment problem with different types of items to be transported from the sources to the destination points. For the optimization of the problem, a goal programming formulation will be presented in which the location selection for each product type will be determined under the multi objective criteria. In the study, we generalize the transshipment model with a variety of product types and finite number of different intermediate nodes between origins and destinations. For the selection of the criteria we selected the costs(fixed cost and transportation cost), location numbers, and unsatisfied demand for each type of products in multi stage transportation, which are the main goals in transshipment modelling problems. The related conditions are also modelled through linear formats.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2000.10b
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• pp.89-100
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• 2000

Recently, marine traffic engineering has been developed until that possible to estimate a change in traffic flow caused from some transformations of the traffic condition and to assess whether changed traffic condition is can be accepted as a useful thing in navigation or not by compute simulation. This paper's main substance is assessment of the present marine traffic safety at these area adjacent to Pusan harbor. Also in this study, it was carried out in order to be convinced of validity of round about TSS to expect changing in traffic flows by the institution of round about TSS and to assess expected traffic flows by using Environmental Stress assessment model.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.95-100
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• 2006

A ship collision avoidance system is developed to control the avoidance action of ship actually and properly in wind forces. The 4-DOF maneuvering equations of motion ar derived to catty out the simulation of the motion of a ship, and the wind forces are considered as the external forces in the simulation. This study suggests a new avoidance system that could include the ship's maneuvering characteristics.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.133-138
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• 2006

Singular value decomposition (SDV) approach is applied to the observability analysis of GPS/INS in this paper. A measure of observability for a subspace is introduced. It indicates the minimum size of perturbation in the information matrix that makes the subspace unobservable. It is shown that the measure has direct connections with observability of systems, error covariance, and singular structure of the information matrix. The observability measure given in this paper is applicable to the multi-input/multi-output time-varying systems. An example on the observability analysis of GPS/INS is given. The measure of observability is confirmed to be less sensitive to system model perturbation. It is also shown that the estimation error for the vertical component of gyro bias can be considered unobservable for small initial error covariance for a constant velocity horizontal motion.

• Journal of Korean Port Research
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• v.12 no.1
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• pp.19-24
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• 1998

The purpose of this study is investigated to suggest the governmental policy and guideline required to establish the coastal zone management and development plan in the Pusan metropolitan city. The results are found as follows; first, a new definition of 'coastal zone' is introduced based on the geophysical characteristics in the city. Second, new policy-oriented guidelines are built on the basis of the coastal function from the viewpoint of the coastal zone management. Third, the coastal zone of the city is classified into 3sub-zone by the geophysical characteristics. Fourth, the comprehensive coastal zone management and development plan is suggested.

• Journal of Korean Port Research
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• v.12 no.1
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• pp.65-73
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• 1998

Pusan Metropolitan City has developed 'HANARO Card' system. It is a sort of multi-function card systems which has devised to resolve many traffic problems, to improve public transportation services, to build advanced transit information systems, to encourage reasonable operation of the public transit companies, and to obtain basic informations for devising transportation policies. This study aims at reviewing the systems of 'HANARO Card', analysing the situation of usage of the card, and suggesting some issues for improving the system. Main finding is that the major effects of the introducing HANARO traffic card are convenience (to pay a charge) in using transit, public parking lots, city freeway toll for citizens, and saving in personnel expenses, maintenance expenses for buses, subway and taxi companies. It is also found that HANARO traffic card system needs to be expended to be compatible with other fields of economic activities.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1998.10a
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• pp.315-322
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• 1998

It is discussed how to route yard-side equipment during the loading operation in port container terminals. The number of containers to be picked up at each yard-bay, as well as the route of a yard-side equipment (for example, transfer crane or straddle carrier) in a yard, are determined. The objective of the problem is to minimize the total container handling time in the yard. An encoding method to represent nodes in the search space is introduced utilizing inherent properties of the optimal solution by which the search space is greatly reduced. A beam search algorithm is suggested. A numerical experiment is carried out to compared the performance of the beam search algorithm with those of other approaches.