• IE interfaces
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• v.19 no.1
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• pp.26-33
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• 2006

Many Firms consider the application of a cross-docking system to reduce inventory and lead-time. However, most studies mainly concentrate on the design of a cross-docking system. This study presents the method that selects the cross-docking center under the existing logistics network. Describing the operation environment to apply the cross-docking system, the selection criteria of the cross-docking center, and the main constraints of transportation planning under the environment of multi-level logistics network, we define the selection problem of the cross-docking center applied to a logistics field. We also define the simulation model that can analyze variously the cross-docking volume and develop the selection methodology of the cross-docking center. The simulation model presents the algorithm and influence factors of the cross-docking system, the decision criteria of the system, policy parameter, and input data. In addition, this study analyzes the effect of increasing the number of simultaneous receiving and shipping docks, and the efficiency of the overnight transportation and cross-docking by evaluating each scenario after simulating the scenarios with the practical data of the logistics field.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.3
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• pp.290-301
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• 2013

The docking analysis of a global ship structure is requested to evaluate its structural safety against the reaction forces at supports during docking works inside a dry dock. That problem becomes more important recently as the size of ships is getting larger and larger. The docking supports are appropriately arranged in a dock to avoid their excessive reaction forces which primarily cause the structural damages in docking a ship and, up to now, the structural safety has been assessed against the support arrangement by the finite element analysis (FEA) of a global ship structure. However, it is complicated to establish the finite element model of the ship in the current structural design environment of a shipyard and it takes over a month to finish the work. This paper investigates a simple and fast approach to carry out a ship docking analysis by a simplified grillage model and to assign the docking supports position on the model. The grillage analysis was considered from the motivation that only the reaction forces at supports are sufficient to assess their arrangement. Since the simplified grillage model of the ship cannot guarantee its accuracy quantitatively, modeling strategies are proposed to improve the accuracy. In this paper, comparisons between the proposed approach and three-dimensional FEA for typical types of ships show that the results from the present grillage model have reasonably good agreement with the FEA model. Finally, an integrated program developed for docking supports planning and its evaluation by the proposed approach is briefly described.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.11a
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• pp.325-328
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• 2003

Fierce competition in today's global markets, the heightened expectation of customers have forced business enterprises to invest in, and focus attentions on, their Supply Chains, Also Cross Docking is an essential part of SC, and integrating Cross Docking with vehicle routing scheduling is needed to smoothly link the physical flow of SC, However, there is no the mathematical model which focuses on Cross Docking with vehicle routing scheduling. Therefore, the integrating model considers Cross Docking and vehicle routing scheduling will be developed in this paper. And the solution based on Tabu algorithm to this model will be provided.

• Journal of the Korea Safety Management & Science
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• v.10 no.4
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• pp.199-207
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• 2008

Many logistics enterprises have made efforts to achieve low costly and high efficient logistics network. The cross-docking system can be a good solution for them. However, it requires tight schedule and all-night operation inevitably for realization of ideal cross-docking. These causes the difficulty of the attainment of daily delivery target and the leave of delivery service persons. In this paper, we develop the line-haul and shuttle service compromised cross-docking model in order to solve the problems practically. We apply the storage process with the cross-docking system and the direct cross-docking between line-haul and shuttle services. The simulation model validates the shorter delivery time by the developed model than the present model.

• Journal of Sensor Science and Technology
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• v.26 no.3
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• pp.199-203
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• 2017

In this paper, we developed an underwater localization system for underwater robot docking using the electromagnetic wave attenuation model. Electromagnetic waves are generally known to be impossible to use in water environment. However, according to the conclusions of the previous studies on the attenuation characteristics in underwater, the attenuation pattern is uniform and its model was accurately proposed and verified in 3-dimensional space via the omnidirectional antenna. In this paper, a docking structure and localization sensor system are developed for a widely used cone type docking mechanism. First, we fabricated electromagnetic wave range sensor transmit modules. And a mobile sensor node is equipped with unmanned underwater vehicle(UUV)s. The mobile node senses the four different signal strength (RSS: Received Signal Strength) from fixed nodes, and the obtained RSS data are transformed to each distance information using the 3-Dimensional EM wave attenuation model. Then, the relative localization between the docking area and underwater robot can be achieved according to optimization algorithm. Finally, experimental results show the feasibility of the proposed localization system for the docking induction by comparing the errors in the actual position of the mobile node and the theoretical position through the model.

• Journal of Advanced Research in Ocean Engineering
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• v.2 no.3
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• pp.150-157
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• 2016

When blocks are supported on a dock, huge reaction forces concentrated at the supports cause structural damage owing to local stress concentrations. Thus, the supports should be arranged to avoid local failure from the reaction forces by redistributing those forces. Docking analyses to determine the proper blocks and their support arrangements are introduced so that the local stresses are minimized to warrant the safety of the docking supports. Local stresses enforced by the support arrangement should be evaluated by finite element analysis (FEA). However, it is difficult to consider an accurate 3D geometry of the blocks in the finite element model because the structural design information is too complicated to determine within several days using the FEA model. This paper presents a simplified FE model to evaluate the safety of the arrangement of supports using a simplified grillage element. The grillage element can be efficiently used to obrain the reaction forces in docking analysis becasuse the reaction forces at the supports are enough to assess the safety of block. Since a simplified grillage model of the entire ship cannot accurately calculate the local stresses, an optimized modeling method based on the grillage element was introduced. The local reaction forces obtained by the proposed approach and three-dimensional FEA were discussed for typical types of ships. It is shown that the reaction forces obtained by the present grillage model are in reasonably good agreement with the FEA model.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.05a
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• pp.1754-1757
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• 2006

Recently many firms operate a cross-docking center in addition to run a distribution center to reduce logistics costs and maintain or enhance logistics service. However, it is true that many firms just operate their cross-docking centers as they are without any change, in spite of that the location of the cross-docking center should be changed and operated when the location of distribution center is changed and moved. This study presents the method that re-selects the location of the cross-docking center when the existing distribution center is changed. Describing the operation environment to apply the cross-docking system and the selection criteria of the cross-docking center under the environment of changeable logistics network, we define the simulation model which can analyze and select the location of the cross-docking center applied to a logistics field. The simulation model presents experiential algorithm selecting the location with the data of the demand point such as volume, transportation costs, and delivery distance.

• Journal of the Korea Safety Management & Science
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• v.19 no.3
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• pp.129-135
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• 2017

The respective delivering vehicle loaded with the own cargo moves into the respective delivery area. At the base, the delivery points D1 and D2, for example, have the same starting point but the destination is different. The average delivering time of the delivery vehicle is mostly more than 8 hours a day. Therefore, the efficiency of delivery is generally low. In this study, the deliveries will be forwarded from a base station to a delivery point where cross docking will be applied to a single vehicle, and will be distributed from the cross docking point through cross docking. If the distribution is implemented, one vehicle will not have to be operated from the base to the cross docking point. In that case, logistics cost will be reasonably saved by the reduction of transportation cost and labor time. If one vehicle only runs from the base to the cross docking point, each vehicle will be operated in two shifts, and the vehicle operation can be efficiently implemented. This research model is based on the assumption that the 3 types of ratios between the traffic volume of the vehicles starting at the base and the vehicles waiting at the cross docking point are set to the first ratio of 30% to 70%, the second ratio of 50% to 50% and the final ratio of 70% to 30%. As a result of the study, The delivery time in the cross docking point is much higher than that in present on the condition that the cargo volume in the D2 area is more than 50%. Likewise, the delivery time is slightly higher on the condition that the cargo volume is less than 50%. Time is reduced in terms of 50% model like AS-IS model.

• Journal of Navigation and Port Research
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• v.48 no.2
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• pp.116-124
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• 2024

Automatic docking of small planing ship is a critical aspect of maritime operations, requiring accurate prediction of motion states to ensure safe and efficient maneuvers. This study investigates the use of Artificial Neural Network (ANN) to predict motion state of a small planing ship to enhance navigation automation in port environments. To achieve this, simulation tests were conducted to control a small planing ship while docking at various heading angles in calm water and in waves. Comprehensive analysis of the ANN-based predictive model was conducted by training and validation using data from various docking situations to improve its ability to accurately capture motion characteristics of a small planing ship. The trained ANN model was used to predict the motion state of the small planning ship based on any initial motion state. Results showed that the small planing ship could dock smoothly in both calm water and waves conditions, confirming the accuracy and reliability of the proposed method for prediction. Moreover, the ANN-based prediction model can adjust the dynamic model of the small planing ship to adapt in real-time and enhance the robustness of an automatic positioning system. This study contributes to the ongoing development of automated navigation systems and facilitates safer and more efficient maritime transport operations.

• Journal of Ocean Engineering and Technology
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• v.30 no.3
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• pp.177-185
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• 2016

In this study, the model developed by Hong (2012) was modified to describe the consecutive docking/undocking situation and was also applied to investigate the effect on seawater circulation in Busan port by consecutive docking/undocking at the connecting bridge of Busan port. Numerical experiments for various docking/undocking cases were performed by dumping the initial concentration within Busan Port and indicated that the concentration in Busan port becomes steady state without numerical wiggles after sufficient time (at least 20 or 30 days). In addition, it was found that the seawater circulation under ship docking was slightly reduced in comparison with that under ship undocking, and the approach time to the target concentration under all the docking cases increased in comparison with the undocking case.