• Title, Summary, Keyword: Docking model

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A Study on Selection of Cross-Docking Center based on Existing Logistics Network (기존 물류 네트워크 기반에서 크로스 - 도킹 거점선정에 관한 연구)

  • Lee, In-Chul;Lee, Myeong-Ho;Kim, Nae-Heon
    • 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.

Parametric Study for Assessment of Reaction Forces on Ship Docking Supports

  • Ryu, Cheol-Ho;Kim, Sung-Chan;Lee, Jang-Hyun
    • 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.

공급 사슬 상에서 Cross Docking을 고려한 Vehicle Routing Scheduling(VRS)

  • 이경민;이영해
    • Proceedings of the Korean Operations and Management Science Society Conference
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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.

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Development of the Enhanced Cross-Docking Model through Compromise between Line-haul and Shuttle Service (간선과 지선간 절충을 통한 개선된 크로스도킹 모델 개발)

  • Kim, Ki-Hong;Shin, Seung-Jun;Choi, See-Yeong;Kang, Kyung-Sik
    • 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.

The Underwater UUV Docking with 3D RF Signal Attenuation based Localization (UUV의 수중 도킹을 위한 전자기파 신호 기반의 위치인식 센서 개발)

  • Kwak, Kyungmin;Park, Daegil;Chung, Wan Kyun;Kim, Jinhyun
    • 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.

Grillage Method Applied to the Planning of Ship Docking

  • Kim, Sung Chan;Ryu, Cheolho;Lee, Jang Hyun;Lee, Kyung Seok
    • 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.

A Study on Selection of Cross-Docking Center by Changing the Logistics Location (물류거점 변경에 따른 크로스-도킹 거점 입지 선정에 관한 연구)

  • Lee In-Cheol;Lee Myeong-Ho;Song Jeong-Eun;Kim Nae-Heon
    • Proceedings of the Korean Operations and Management Science Society Conference
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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.

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Study for determining cross docking point local bases approach (크로스도킹 거점 결정을 위한 연구 -지역거점을 중심으로-)

  • Kim, Ki-Hong
    • 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.

Effect of Consecutive Ship Docking and Undocking on Seawater Circulation in Harbor (선박의 연속적 접⋅이안이 항내 해수순환에 미치는 영향)

  • Hong, Namseeg
    • 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.

A Development of Docking Phase Analysis Tool for Nanosatellite

  • Jeong, Miri;Cho, Dong-Hyun;Kim, Hae-Dong
    • Journal of Astronomy and Space Sciences
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    • v.37 no.3
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    • pp.187-197
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    • 2020
  • In order to avoid the high cost and high risk of demonstration mission of rendezvous-docking technology, missions using nanosatellites have recently been increasing. However, there are few successful mission cases due to many limitations of nanosatellites like small size, power limitation, and limited performances of sensor, thruster, and controller. To improve the probability of rendezvous-docking mission success using nanosatellite, a rendezvous-docking phase analysis tool for nanosatellites is developed. The tool serves to analyze the relative position and attitude control of the chaser satellite at the docking phase. In this tool, the Model Predictive Controller (MPC) is implemented as a controller, and Extended Kalman Filter (EKF) is adopted as a filter for noise filtering. To verify the performance and effectiveness of the developed tool for nanosatellites, simulation study was conducted. Consequently, we confirmed that this tool can be used for the analysis of relative position and attitude control for nanosatellites in the rendezvous-docking phase.