• Journal of Ocean Engineering and Technology
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• v.16 no.5
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• pp.21-33
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• 2002

In this paper, an analytical solution for the wave-induced seabed response in a porous seabed is derived. Unlike previous investigations with quasi-static soil behaviour, dynamic soil behaviour is considered in the new solution. The basic one-dimensional framework proposed by Zienkiewicz et al (1980) is extended to two-dimensional cases. Based on the analytical solution derived, the effects of dynamic soil behaviour on the wave-induced seabed response are examined. The boundary of quasi-static soil behaviour and dynamic soil behaviour is clarified, and formulated for engineering practice.

• Journal of the Society of Naval Architects of Korea
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• v.28 no.1
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• pp.169-181
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• 1991

In this study, an analytical solution of pre-buckling, buckling, post-buckling, ultimate strength and post-ultimate strength behaviour of simply supported rectangular plates subjected to biaxial compression is derived. Parametric study with varying the aspect ratio, the slenderness ratio and the loading ratio is carried out. The present solution may be used as basical data when the verfication of the numerical and experimental result is made.

• International Journal of Ocean Engineering and Technology Speciallssue:Selected Papers
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• v.5 no.1
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• pp.1-13
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• 2002

In this paper, an analytical solution for the wave-induced seabed response in a porous seabed is derived. Unlike previous investigations with quasi-static soil behaviour, dynamic soil behaviour is considered in the new solution. The basic one-dimensional framework proposed by Zienkiewicz et al (1980) is extended to two-dimensional cases. Based on the analytical solution derived, the effects of dynamic soil behaviour on the wave-induced seabed response are examined. The boundary of quasi-static soil behaviour and dynamic soil behaviour is clarified, and formulated for engineering practice.

• Journal of Distribution Science
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• v.11 no.8
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• pp.15-23
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• 2013

Purpose - This is a case study aimed at finding a solution for improving the pallet loading efficiency in the process of delivering products through a transshipment using the T-11 and T-12 pallet systems. The study proposes a solution by demonstrating the case of a certain manufacturer A, who aims to reduce the logistics cost by using packaging sizes that are commonly applicable and can improve the compatibility between the T-11 pallet system, designated as the standard pallet in Korea, and the T-12 pallet system, which is commonly used in other foreign countries. The use of common sizes increases compatibility among the two systems and reduces both logistics and environmental costs. Thus, this case study calculates the quantitative benefits of applying common packaging sizes to improve the compatibility between the T-11 and T-12 pallet systems. These systems are considered to be the most important and widely used transportation systems in the global logistics industry. Research design, data, and methodology - This study examined manufacturer A's representative product and delivery system and assessed how manufacturer A was affected by the use of incompatible packaging sizes in the T-11 (1100 mm×1100 mm) and T-12 (1200mm×1000 mm) pallet systems, which were specified in the KS T 1002 standard. In addition, this study analyzed the impact of these packaging sizes on A's logistics cost. The TOPS program (Total Packaging System) was used to simulate pallet loading efficiency,and the main parameter studied was volume, as calculated from length, width, and height. Results - When the sizes of secondary packaging were not compatible across the T-11 and T-12 pallet systems, a reduction in loading efficiency was observed, leading to an increase in logistics cost during transshipment. Such low loading efficiencies led to a further loss of efficiency in transportation, storage and unloading. This may have a possible environmental impact with high social expenses, such as increased CO₂ emissions. Hence, this study proposed that the KS T 1002 standard be amended to include 21 packaging sizes, including 7 sizes of the 600 mm×500 mm category, which are compatible with both the T-11 and T-12 pallet systems. Conclusions - This study found that the 69 standard sizes under the T-11 pallet system and the 40 standard sizes under the T-12 system in the KS T 1002 standard can be simplified and reduced to 21 mutually compatible packaging sizes, enabling logistics standardization and reducing national-level logistics costs. If the government pays attention to this study and considers the standardization of common sizes for the T-11 and T-12 pallet systems and amends the KS T 1002 standard, this study will deliver practical value to the global logistics industry, apart from being of academic significance.

• Journal of the Korean Ceramic Society
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• v.55 no.3
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• pp.185-202
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• 2018

Photoelectrochemical (PEC) cells can convert solar energy, the largest potential source of renewable energy, into hydrogen fuel which can be stored, transported, and used on demand. In terms of cost competitiveness compared with fossil fuels, however, both photocatalytic efficiency and cost-effectiveness must be achieved simultaneously. Improvement of cost-effective, scalable, versatile, and eco-friendly fabrication methods has emerged as an urgent mission for PEC cells, and solution-based fabrication methods could be capable of meeting these demands. Herein, we review recent challenges for various nanostructured oxide photoelectrodes fabricated by solution-based processes. Hematite, tungsten oxide, bismuth vanadate, titanium oxide, and copper oxides are the main oxides focused on, and various strategies have been attempted with respect to these photocatalyst materials. The effects of nanostructuring, heterojunctions, and co-catalyst loading on the surface are discussed. Our review introduces notable solution-based processes for water splitting photoelectrodes and gives an outlook on eco-friendly and cost-effective approaches to solar fuel generation and innovative artificial photosynthesis technologies.

• Wind and Structures
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• v.22 no.3
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• pp.349-368
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• 2016

A preconditioning technique is presented for a simultaneous solution to wind-membrane interaction. In the simultaneous equations, a linear elastic model was employed to deal with the fluid-structure data transfer at the interface. A Lagrange multiplier was introduced to impose the specified boundary conditions at the interface and strongly coupled simultaneous equations are derived after space and time discretization. An initial linear elastic model preconditioner and modified one were derived by treating the linearized elastic model equation as a saddle point problem, respectively. Accordingly, initial and modified fluid-structure interaction (FSI) preconditioner for the simultaneous equations were derived based on the initial and modified linear elastic model preconditioners, respectively. Wind-membrane interaction analysis by the proposed preconditioners, for two and three dimensional membranous structures respectively, was performed. Comparison was made between the performance of initial and modified preconditioners by comparing parameters such as iteration numbers, relative residuals and convergence in FSI computation. The results show that the proposed preconditioning technique greatly improves calculation accuracy and efficiency. The priority of the modified FSI preconditioner is verified. The proposed preconditioning technique provides an efficient solution procedure and paves the way for practical application of simultaneous solution for wind-structure interaction computation.

• Journal of the Korea Society of Computer and Information
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• v.20 no.10
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• pp.61-68
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• 2015

This paper deals with the pre-marshalling problem that the containers of container yard at container terminal are relocated in consensus sequence of loading schedule of container vessel. This problem is essential to improvement of competitive power of terminal. This problem has to relocate the all of containers in a bay with minimum number of movement. There are various algorithms such as metaheuristic as genetic algorithm and heuristic algorithm in order to find the solution of this problem. Nevertheless, there is no unique general algorithm that is suitable for various many data. And the main drawback of metaheuristic methods are not the solution finding rule but can be find the approximated solution with many random trials and by coincidence. This paper can be obtain the solution with O(m) time complexity that this problem deals with bin packing problem for m stack bins with descending order of take out ranking. For various experimental data, the proposed algorithm can be obtain the optimal solutions for all of data. And to conclude, this algorithm can be show that most simple and general algorithm with simple optimal solution finding rule.

• Advances in concrete construction
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• v.15 no.2
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• pp.115-126
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• 2023

This paper investigates creep analysis of a plate made of Al-SiC functionally graded material using Mendelson's method of successive elastic solution. All mechanical and thermal material properties, except Poisson's ratio, are assumed to be variable along the thickness direction based on the volume fraction of reinforcement and thickness. First, the basic relations of the plate are derived using the Love-Kirchhoff plate theory. The solution of governing equations yields an elastic solution to start creep analysis. The creep behavior is demonstrated through Norton's equation based on Pandey's experimental results extracted for Al-SiC functionally graded material. A linear variation is assumed for temperature distribution along the thickness direction. The creep strain, as well as the thermal strain, are included in the governing equations derived from classical plate theory for mechanical strain. A successive elastic solution based on Mendelson's method is employed to derive the history of stresses, strains, and displacements over a long time. History of stresses and deformations are obtained over a long time to predict damage to the plate because of various loadings, and material composition along the thickness and planar directions.

• Journal of Embryo Transfer
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• v.14 no.3
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• pp.145-153
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• 1999

This study was conducted to investigate the effects of vitrification solution and developmental stage on the survival rate of vitrified-thawed human blastocyst embryos. Human blastocyst embryos were cryopreserved by vitrification using EFS and GE solution, and their survival rates were examined after thawing and further culture. EFS solution was consisted of 40% ethylene glycol, 18% Ficoll 70 and 0.3M sucrose. GE solution was consisted of 25% glycerol and 25% ethylene glycol. Embryos were exposed to EFS and GE solution by 2 steps and 3 steps, respectively, and plunged into liquid nitrogen after loading into 0.25ml plastic straws. Blastocysts were classified into 4 groups in accordance with their developmental stage: into 1) EEB, 2) MEB and 3) EdB, of blastocysts developed on day 5, and 4) 6d-Bla(the blastocysts which formed on day 6). The blastocysts at each stage were vitrified by GE solution and cryopreserved in LN2. After thawing them, we examined their survival rates, respectively. The resulted of this study were as follows: 1. The survival rate of blastocysts vitrified by GE solution was 64.4%, significantly higher than that (5.7%) vitrified by EFS solution (P<0.001). 2. When the blastocysts were vitrified by GE solution according to each developmental stage, the survival rates of EEB, MEB, EdB and 6d-Bla were 65.9%, 65.9%, 73.2% and 58.1%, respectively. In conclusion, the cryopreservation of human blastocysts by vitrification is likely to have a marked advantage in terms of cost, work and time as compared to the conventional slow freezing in IVF-ET programs.

• Journal of Navigation and Port Research
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• v.28 no.6
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• pp.531-539
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• 2004

In this paper, we propose a new heuristic solution for 3D container packing problem for the variable sizes and types of freight. Frist of all, we consider the total cost of container charge i.e., handling, loading and transportation, where each freight will be specifically identified The types of containers and its number to be loaded am be selected automatically by minimizing the total cost of container charge. Maximization of loading space am be achieved efficiently by operating the palletizing and/or depalletizing of freight. By considering these factors we can determine the position of freight in the container and the loading sequence to be packing into the container. In container packing simulation, we can verify that the proposed heuristic algorithm indicates more efficiency space utilization and shows the possibility of using on commercial business.