• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2004년도 추계학술대회
• /
• pp.1710-1714
• /
• 2004

The analysis of ventilation performance varying with duct shapes in reefer container of scale-model has studied experimentally. Most container ships have ventilation system of which ducts extended to the bottom for the purpose of efficient exhausting of condensing heat from hold. However, the size of ducts is so over-long that it causes manufacturing troubles. In this study, for various types of duct, flow visualization using smoke and normalized temperature analysis are presented. Finally, the cooling performance are compared respectively.

• 한국항해항만학회지
• /
• 제28권7호
• /
• pp.587-591
• /
• 2004

In order to measure the performance of resources in a port container terminal, we conducted a state transition network simulation to model various equipment processes. The processes that container cranes and transfer cranes perform are idle, wait, move, and work. Vehicles perform idle, wait, empty travel, and full travel. Because cranes, vehicles, and vessels are movable entities and all equipment is classified as either a customer or server, we separated the various stages of the process based upon the state transition network To validate the simulation results, a real system was used to illustrate the use of various measurements using the state transition network.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2004년도 춘계학술대회 논문집
• /
• pp.465-470
• /
• 2004

본 논문에서는, 컨테이너 터미널에서 운행되는 컨테이너크레인의 자동화 시스템을 개방형 제어시스템으로 제안한다. 그리고, 개방형 제어시스템을 하드웨어 모듈과 OS 모듈 그리고 응용소프트웨어 모듈로 구성되는 표준모델로 제시한다. 본 논문의 기여도는 다음과 같다. 첫째, 크레인 제어시스템의 개방화를 위한 새로운 기준모델을 제안한다. 둘째로, 컨테이너크레인의 구조를 분석하고 자동화된 컨테이너크레인을 구현하기 위한 방법을 제안한다.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 1999년도 춘계학술대회논문집
• /
• pp.257-260
• /
• 1999

It is very important to design the shape of container in HIPing process since the final shape and relative density distribution of the product are decisively dependent on the shape of container. A derivative based approach to determine the shape of container in HIPing process is presented. In this approach the optimal design problem is formulated on the basis of the finite element process. The process model the formulation for process optimal design and the schemes for the evaluation of the design sensitivity and an iterative procedure for optimization are described. In comparison with finite difference scheme the validity of the schemes for the evaluation of the design sensitivity is examined.

• 한국해양공학회지
• /
• 제34권2호
• /
• pp.120-127
• /
• 2020

Evaluation of fatigue strength considering the springing effect of very large container ships is crucial in the design stage. In this study, we established a fatigue strength evaluation method considering a linear springing component in the frequency domain. Based on a three-dimensional global model, a fluid-structure interaction analysis was performed and the modal superposition method was applied to determine the hot spot stress at the hatch corner of very large container ships. Fatigue damage was directly estimated using the stress transfer function with a linear springing response. Furthermore, we proposed a new methodology to apply the springing effect to fatigue damage using hull girder loads. Subsequently, we estimated the fatigue damage contribution due to linear springing components along the ship length. Finally, we discussed the practical application of the proposed methods.

• 대한조선학회 특별논문집
• /
• 대한조선학회 2007년도 특별논문집
• /
• pp.32-42
• /
• 2007

Container vessels are required to have a large KMT to load many containers which requires a wide transom stern form. The wide transom stern generates large stern waves particularly at the scantling draft. This means that reducing the stern wave leads to resistance reduction. Numerical analyses and Model tests for duck-tail of the stern part have been performed to reduce the resistance of the container vessel having the wide transom on the scantling draft and optimize the form of duck-tail with the change of the design parameter i.e. length and edge height. The optimized duck-tail increases the speed by 0.8 % at scantling draft.

• Industrial Engineering and Management Systems
• /
• 제11권1호
• /
• pp.103-113
• /
• 2012

A yard in a container terminal is a temporary storage space before containers are loaded onto the target vessel or delivered to consignees. For improving the utilization of the space in the yard and the efficiency of loading and discharging operations, it is important that operation plans must be carefully constructed in advance. A heuristic method is suggested to solve operation space planning problems considering workloads on handling equipment as well as space availabilities. The operation plans in this paper includes quay crane (QC) schedules and space plans for multiple vessels considering the workload in the container yard of container terminals. This paper evaluates the effectiveness of a space planning method and the performance of a new QC scheduling method using a simulation model.

• 한국항해항만학회지
• /
• 제43권2호
• /
• pp.101-109
• /
• 2019

Seaports play a vital role in the economic development of countries, especially for countries having long coastlines such as Vietnam Seaport industry in Vietnam has witnessed an impressive development in recent years. The national cargo throughput in the period 2013-2017 achieved a compounded annual growth rate (CAGR) of 11.8%/year, higher than that of the world (5.1%). However, the differences in planning policies and infrastructure systems has led to the differences in port performance efficiency of regional ports. Therefore, it is necessary to have a general and accurate view of the picture of Vietnam's seaport. The objective of this study was to analyze the relative efficiencies of 26 Vietnam container terminals using traditional output-oriented CCR and BCC DEA model. Malmquist P roductivity Index (MP I) was also applied to evaluate changes in container terminals productivity over time.

• Nuclear Engineering and Technology
• /
• 제54권6호
• /
• pp.2120-2134
• /
• 2022

A hypothetical core destructive accident (HCDA) has received widespread attention as one of the most serious accidents in sodium-cooled fast reactors. This study combined recent advantages in numerical methods to realize realistic modeling of the complex fluid-structure interactions during HCDAs in a full-scale sodium-cooled fast reactor. The multi-material arbitrary Lagrangian-Eulerian method is used to describe the fluid-structure interactions inside the container. Both the structural deformations and plug rises occurring during HCDAs are evaluated. Two levels of expansion energy are considered with two different reactor models. The simulation results show that the container remains intact during an accident with small deformations. The plug on the top of the container rises to an acceptable level after the sealing between the it and its support is destroyed. The methodology established in this study provides a reliable approach for evaluating the safety feature of a container design.

• 한국식품저장유통학회지
• /
• 제20권3호
• /
• pp.289-295
• /
• 2013

차압예냉시스템을 설계하기 위해서는 송풍저항을 정확하게 예측해야 하며, 송풍저항은 청과물의 적재방법에 따라 크게 달라진다. 본 연구는 차압예냉시스템에서 송풍량에 따른 송풍저항식과 상자의 적재방법별로 송풍저항을 측정할 수 있는 모델을 개발하기 위하여 수행되었다. 공을 퇴적한 모형상자에서의 송풍저항은 빈 상자에서의 송풍저항과 공 퇴적층만의 송풍저항을 합한 값보다 1.5배 정도 높게 나타났다. 또한, 적재상자에서의 송풍저항은 통기폭 방향 적재상자수의 증가에 따라 지수적으로 증가하였으나, 적재길이와 적재높이의 영향은 거의 받지 않았다. 상자를 2열로 적재하는 차압예냉시스템에서 송풍저항은 1개 상자에서의 송풍저항을 기초로 예측이 가능하였으며, 예측모델을 제시하였다.