• Journal of Korea Port Economic Association
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• v.23 no.4
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• pp.23-47
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• 2007

We analyzed the questionnaire survey for the current maintenance of Incheon port's loading and unloading equipments and the possibility of TPM(Total Productive Maintenance) application. And also, We certificated Structural Equation Model with computer packages. Results of the survey indicated that the current maintenance of Incheon port's loading and unloading equipments was not good. We recognized the relationship of contextual factors about the productivity of the loading and unloading equipments The productivity of the loading and unloading equipment positively depends on maintenance management of equipments, but the organization and personnel management does not have a influence on the productivity of the loading and unloading equipment. So we suggest TPM as the future maintenance methodology of equipments. Using TPM to the loading and unloading equipments, we will try to improve the methodology of the organization and personnel management.

• Journal of the Society of Naval Architects of Korea
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• v.51 no.3
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• pp.179-183
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• 2014

The fluid loading effect has been investigated for the shipboard equipment foundation mobility with finite element model. For the purpose, two kinds of finite element models for 60m class ship have been developed: global and local model. The former is for low frequency range and the latter for middle frequency range. These finite element models contain added mass explaining fluid loading effect. Added mass has been implemented with virtual mass matrix derived from Laplace equation governing fluid surrounding ship hull. The mobility assessment result for diesel generator foundation of the objective model shows that the fluid loading effect should be considered, especially in low frequency range, to more accurately assess shipboard equipment foundation mobility.

• Nuclear Engineering and Technology
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• v.55 no.8
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• pp.2905-2918
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• 2023

The valve assembly used in nuclear power plants is important safety-related equipment. In the new standard, the physical attributes are measured using a valve diagnosis test, which is used in the expansion to other non-tested valves using a quantitative test-basis methodology. With a motor-operated actuator, the state of stem's lubrication is related to physical attributes such as the stem factor and the friction coefficient. This study analyzed the numerical transient of fluid and solid lubrication with a squeeze film effect due to the loading rate on the stem and the stem nut using the experimental data. The differential equation that governs the motion mechanism of the stem and stem nut is established and analyzed. The flow rate, the fluid and the solid contact forces are calculated with the friction coefficient. Finally, we found that a change in the friction coefficient results from a change of the shear force in the solid contact mode during the interchange process between the solid contact mode and the fluid contact mode. The qualitative understanding of the squeeze film effect is expanded quantitatively for forces, thread surface distance, velocity, and acceleration, with consideration of the metal solid contact and fluid contact.

• Geomechanics and Engineering
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• v.2 no.3
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• pp.203-211
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• 2010

An experimental program of isotropic loading tests on a compacted kaolin using a conventional triaxial equipment modified for testing unsaturated soils was perform to investigate a loading collapse curve of unsaturated soils along wetting and drying paths. The test data are presented in terms of effective stress on a range of constant suction. The suction hardening behavior was observed for both wetted and dried samples. With the use of an appropriate effective stress parameter, the unique relationship for loading collapse curve for wetting and drying processes was obtained.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.29-30
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• 2008

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.539-542
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• 2004

Nowadays, High-rise building becomes higher and bigger than ever. As a result, lots of construction materials are needed at the same times. Because of divided diverse process of construction, several different Processes concur simultaneously with complexity of procurement. So, effective construction material supply and lift-up are essential part of the spot. Especially, when ending part of construction, there are much conflict between finishing and equipment materials also problems of folding lift-up. The Purpose of this paper is suggesting better effective lift-up system through analysis of loading factors.

• KCI Concrete Journal
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• v.14 no.1
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• pp.8-14
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• 2002

This is the first of two part series on experimental studies of grout type transverse joints. In this study, grout type transverse joints between precast concrete slabs are statically tested to determine the cracking loads and ultimate shear capacities of the grout type transverse joints. The tests are performed with a loading equipment designed and constructed especially in the lab to induce shear failures on the joints of the test specimens. Shape of the transverse joints, grouting materials and amount of prestress are selected as test parameters for the study. The results indicate that epoxy is an excellent grouting material which can be used in limited locations where large tensile stress is acting on the slab. Longitudinal prestressing is also an effective method to increase the shear strength of the transverse joints. A rational method to estimate the cracking and ultimate loads for the design of grout type transverse joints is proposed based on the static loading tests. Success of the tests with shear loading equipment allowed continuing the research further onto the fatigue strength of the grout type joints, which will be presented in the second part of the paper.

• Journal of Korea Port Economic Association
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• v.33 no.1
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• pp.1-10
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• 2017

The dynamic nature of mechanization and automation to improve productivity and safety within logistics centers, has necessitated various studies to support efficient and safe working conditions for workers. However, accidents in the loading dock occur frequently as workers and forklift trucks operate within the same space. This research introduces cargo batch loading and unloading systems, which enable increasing productivity and safety through the use of mechanization and automation in the loading dock. To assist efficient operation of this new system, four pieces of general-purpose equipment or three pieces of dedicated equipment are deemed to be essential. Moreover, the floor area of the loading dock is designed to accommodate $256.28m^2$ and $207.00m^2$ for the general-purpose and dedicated systems respectively, in addition to the space allocated for equipment and additional space. The design of the loading dock considers the area of the loading dock as well as the cargo batch loading and unloading systems. Economic analysis, such as NPV, IRR, and PBT, were conducted in addition to sensitivity analysis on key variables.

• 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.

• Steel and Composite Structures
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• v.39 no.3
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• pp.229-241
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• 2021

This work focused on aluminum foam sandwich (AFS) with different foam core densities and different face-sheet thicknesses subjected to constant amplitude three-point bending cyclic loading to study its fatigue performance. The experiments were conducted out by a high frequency fatigue test machine named GPS-100. The experimental results showed that the fatigue life of AFS decreased with the increasing loading level and the structure was sensitive to cyclic loading, especially when the loading level was under 20%. S-N curves of nine groups of AFS specimens were obtained and the fatigue life of AFS followed three-parameter lognormal distribution well. AFS under low cyclic loading showed pronounced cyclic hardening and the static strength after fatigue test increased. For the same loading level, effects of foam core density and face-sheet thickness on the fatigue life of AFS structure were trade-off and for the same loading value, the fatigue life of AFS increased with aluminum foam core density or face-sheet thickness monotonously. Core shear was the main failure mode in the present study.