• Journal of the Korean Society of Safety
• /
• v.18 no.1
• /
• pp.101-107
• /
• 2003

Dynamic behavior of flexible rectangular liquid storage structures is analysed by the developed method. The rectangular liquid storage structures are assumed to be fixed to the ground and a moving coordinate system is used. The irrotational motion of invicid and incompressible ideal fluid is represented by two analytic solutions. One is the solution of the fluid motion in the rigid rectangular liquid storage structure due to ground motions and the other is the solution of the fluid motion by the motion of the wall in the flexible rectangular liquid storage structure. The motion of structure is modeled by finite elements. The fluid-structure interaction effect is reflected into the coupled equation of motion as added fluid mass matrix. The free surface sloshing motion and hydrodynamic pressure acting on the wall in the flexible rectangular liquid storage structure due to the horizontal ground motion are obtained by the developed method and verified.

• Transactions of the Korean hydrogen and new energy society
• /
• v.13 no.1
• /
• pp.90-99
• /
• 2002

In order to utilize hydrogen energy in a large-scale in the future, development of effective hydrogen storage method is essentially required as well as that of efficient hydrogen production method. The hydrogen storage method using metal hydrides has been holding the spotlight as a safer and higher-density hydrogen storage method than conventional hydrogen storage methods such as liquid hydrogen or compressed hydrogen storage method. However when metals react with hydrogen to store hydrogen as metal hydrides, they undergo exothermic reactions, while metal hydrides evolve hydrogen by endothermic reaction. Therefore, hydrogen storage tank should have such structure that it can absorb or release reaction heat rapidly and efficiently. In this study, a review on the improvement of the heat release and absorption structure in the hydrogen storage tank was conducted, and as a result, a new type of hydrogen storage tank with the structure of vertical-type wall was designed and manufactured. Experimental results showed that this new type of tank could be used as an efficient hydrogen storage tank because its structure is simpler and manufacture is easier than cup-type hydrogen storage tank with the structure of packed horizontal cup.

• The Transactions of the Korea Information Processing Society
• /
• v.6 no.4
• /
• pp.851-867
• /
• 1999

Numerous proposals for extending the relational data model as well as conceptual and object-oriented data models have been suggested. However, there has been relatively less research in the area of defining segmented storage structure and data migration strategies for temporal data. This paper presents the segmented storage structure in order to increment search performance and the two data migration strategies for segmented storage structure. this paper presents the two data migration strategies : the migration strategy by Time granularity, the migration strategy by LST-GET. In the migration strategy by Time Granularity, the dividing time point to assign the entity versions to the past segment, the current segment, and future segment is defined and the searching and moving process for data validity at a granularity level are described. In the migration strategy by LST-GET, we describe the process how to compute the value of dividing criterion. searching and moving processes are described for migration on the future segment and the current segment and entity versions 새 assign on each segment are defined. We simulate the search performance of the segmented storage structure in order to compare it with conventional storage structure in relational database system. And extensive simulation studies are performed in order to compare the search performance of the migration strategies with the segmented storage structure.

• Journal of the Korean Society of Safety
• /
• v.19 no.4 s.68
• /
• pp.109-116
• /
• 2004

The dynamic behavior of the rectangular liquid storage structure is known to be greatly influenced by fluid-structure interaction. By mounting the liquid storage structure on the properly designed base isolators, dynamic response of the superstructure can be reduced. However, base isolators inevitably incur large displacement of the structure to the ground ·ind may give adverse effects on the sloshing height. This paper presents the analysis method for fluid-structure-isolator interaction in base-isolated rectangular liquid storage structures. In the method, the irrotational motion of invicid and incompressible ideal fluid is expressed by analytic solutions and the superstructure and isolators are properly modeled by finite element and bilinear model. Free surface sloshing motion, hydrodynamic pressure acting on the wall and structural response are obtained by the presented method.

• The Journal of Fisheries Business Administration
• /
• v.30 no.1
• /
• pp.119-147
• /
• 1999

This article is subject to the rationalization of the cold-storage warehouse management, which gives the stabilization of the fishery production and the food life with respect to fisheries industry. In this point of view, the article examines to the structure of the cold-storage warehouse industry from the perspective of the industrial organization. To put it concretely, the article intends to apprehend the state of the structure of the industry and analyze the cold-storage warehouse's management activities. In addition, I try to find know the factors that affect the management performance(profitablity) of the industry through the cross-sectional correlation analysis. Finally, the conclusion of the article can be described as follows : \circled1 On the basis of the cold-storage capacity, there is the tendency that the industry concentrate in the area of Pusan(41.7%). \circled2 By formulating step of development of the industry, it is divided by six types. Type I is designed as raw material-storage warehouse for self-processing. Type IIis the raw material-storage warehouse for self-processing and storage-sale warehouse. Type III is the raw material-storage warehouse for self.distribution. Type IV is the raw material-storage warehouse for self-distribution and storage-sale warehouse. Type V is the net storage-sale warehouse. Type Ⅵ is the physical distribution center warehouse. Although each region has one representative type,6 types exist in all regions. \circled3 The competition structure of the industry has double structure on the basis of cold-storage capacity. \circled4 With respect to the management activity of the cold-storage warehouse, there is no change or even a decrease not increasing or not any change in sales from 1996 to 1997 \circled5 In order to try to induce the amount of shipper's materials, services that a cold-storage warehouse supply with its users include a custody-fee discount, a distribution-process service, a finance service, quality management service and so on. One of the best attractive services is the custody-fee service. \circled6 In the structure and management activity of the industry, the factors that affect management performance (profitablity) are a custody-fee discount, sales ability and capital structure of individual firm. Positive factor is sales ability and capital structure of individual firm. But, The custody-fee discount turns out to be a negative capital structure of individual film.

• 전기의세계
• /
• v.31 no.4
• /
• pp.281-287
• /
• 1982

PASCAL has a recursive nested structure and uses deep binding of identifiers. This paper studies the problems and techniques in storage management for PASCAL on the IBM 370 system, and presents run-time storage administration algorithms which use stack scheme and heap efficiently on the view of storage. The stack-scheme was used to implement the feature of recursive nested structure and the heap was used to implement the feature of the dynamic allocation procedure and pointer variable, allowing an additional dynamic storage recovery procedure.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.22 no.6
• /
• pp.763-770
• /
• 1993

To investigate the quality changes during frozen storage, top shell, Omphalius pfeifferi capenteri, was stored at -18$^{\circ}C$, -$25^{\circ}C$ and -3$0^{\circ}C$ immediately after shelling and water holding capacity, protein composition and histological features were examined with the lapsed period of the storage. During the storage period, amount of free drip was increased with higher frozen temperature and longer frozen period, but with the longer storage period, the lower water holding capacity was observed. The extractability and composition of muscle protein, sarcoplasmic protein and stroma protein were rather stable regardless of frozen temperature and frozen storage period. However, the extractability of myofibrillar protein was decreased with higher frozen temperature and longer frozen storage period. On the changes of muscle tissue structure, following points were observed. 1) In the muscle tissue structure of fresh sample, fine muscle fiber was closely distributed all over the tissue regardless of cross and longitudinal section. 2) In tissue structure under frozen state, it was observed that ice crystals apparently grew with the higher storage temperature. Empty spaces between muscle bundles which wee formed by aggregations of muscle fiber were observed after 3 months storage at -18$^{\circ}C$ . 3) Tissue structure in thawed state was restored satisfactorily after 1 month storage regardless of storage temperature. After 3 months storage at -3$0^{\circ}C$, muscle tissue was well restored, but at -18$^{\circ}C$, empty spaces were apparent due to incomplete restoration.

• Proceedings of the KSME Conference
• /
• 2000.11a
• /
• pp.475-480
• /
• 2000

The transient dynamic-response analysis of fuel-storage tanks of flying vehicles accelerating in the vertical direction is achieved with finite element method. A fuel-storage tank is a representative example of the fluid-structure interaction problem, in which structure and fluid media interact strongly. For the accurate analysis of this complicated fluid-structure system, we employed ALE(arbitrary Lagrangian-Eulerian) coupling method. Two types of fuel-storage tanks, one with two baffles and the other without baffle, are considered to examine the effect of baffles. The fuel-storage tank with baffles shows more uniform hydrodynamic pressure distribution, resulting effective stress in structural region and faster convergence from transient to steady states. MSC/Dytran, a commercial FEM software for the 3D coupled dynamic analysis, is used for this analysis.

• Journal of the Korean Society of Safety
• /
• v.28 no.6
• /
• pp.49-56
• /
• 2013

The statistics of recent accidents in warehouses show that a heavy toll of lives were produced by various accidents, e.g. collision, overturn, fall, slip, exposure to harmful substances or environments, etc. Of significant concern amongst them is the collision, especially the collision between forklift and storage rack structure. Accordingly, this study focuses on behavioral characteristics of rack structure subjected to dynamic impact loading of a forklift. For this purpose, time-domain response analysis has been performed on a standard 2-bay six-story rack structure consisting of columns, beams and bracing members with perforated open section. In order to investigate the most critical scenario, the impact loads are applied in both down-aisle and cross-aisle directions, and the impact locations are also varied along the shelves of the palettes. In order to deal with storage distributions, three types of rack structures are further taken into account: original empty rack structure with no storage, half-loaded rack structure and fully-loaded rack structure. The numerical simulation results demonstrate that the dynamic characteristics of the rack structure are significantly dependent on the distribution of the storage goods and its natural period varies from 0.24sec to 1.06sec, approximately 4.4 times. Further, the parametric studies show that the forklift impact is most critical to the safety of the rack structure when it collides either at the base or at the top of the rack structure.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2023.05a
• /
• pp.411-412
• /
• 2023

The purpose of this research and development is to develop a structure module that improves the efficiency and constructability of the layout structure as well as the design development of rainwater permeable storage tank blocks using inorganic binders and aggregates with the aim of reducing greenhouse gas (CO₂) with eco-friendly materials. In addition, for the efficient response to flooding of the developed permeable storage structure, we present a technical solution for combining drone mapping technology and flood monitoring technology that can analyze topographical factors in detail.