• Proceedings of the Korea Concrete Institute Conference
• /
• 1990.10a
• /
• pp.123-124
• /
• 1990

Seaside concrete structure is deteriorated by chloride-ion, sulphate and salt cristalization in concrete pore. Therefore the amount of these chemical substance should be analyzed for evaluating the durability of seaside concrete structure. In this study, the amount of chloride-ion in concrete was surveyed in order to estimate the damage state of concrete structure within am influence of seawater.

• Journal of Ocean Engineering and Technology
• /
• v.35 no.3
• /
• pp.191-202
• /
• 2021

Studies on very large offshore structures are increasing owing to the development of deep sea, large-scale energy generation using ocean resources, and so on. The enlargement of offshore structures makes the hydroelastic effect and low natural frequency related responses important. Numerical analyses and model tests for hydroelastic and higher-order springing responses of fixed cylindrical structures are conducted in this study. The panel methods with and without the hydroelastic effect with shell elements, and the Morison analysis method with beam elements are applied. To observe the hydroelastic effect for structural strength, two structures are considered: bottom-fixed cylindrical structures with high and low bending stiffnesses, respectively. The surge motions at the top of the structure and bending stresses on the structure are observed under regular and irregular wave conditions. The regular wave conditions are generated considering the ratios of the cylindrical outer diameter to the wave lengths, and keeping the wave steepness constant. The model tests are performed in the three-dimensional ocean engineering basin in the KRISO (Korea Research Institute of Ships and Ocean Engineering). From the numerical and experimental results, in which the hydroelastic responses are only observed in the case of the structure with a low bending stiffness, it is confirmed that the hydroelastic responses are highly dependent on the structural stiffness. Additionally, the higher-order phenomenon on the specified wave condition is analyzed by observing the higher-order springing responses when the incident wave frequency or its multiples with the high wave height coincides with the natural frequency of the structure.

• Nuclear Engineering and Technology
• /
• v.54 no.7
• /
• pp.2427-2434
• /
• 2022

Series of unequal quantity Nd/Ce co-doped ceramic nuclear waste forms, (Gd, Nd)₂(Zr, Ce)₂O₇, were prepared to tailor its ordered pyrochlore or disordered fluorite structure. The phase transition, microtopography, and elemental composition of the ceramic samples were systematically investigated, especially the effect of order-disorder structure on the chemical stability. It was confirmed that unequal quantity of Nd/Ce could synchronously replace the Gd/Zr-sites of Gd₂Zr₂O₇. And the phase transition of order-disorder structure could be successfully tailored by regulating the average cationic radius ratio of (Gd, Nd)₂(Zr, Ce)₂O₇ series. The elements of Gd, Nd, Zr, and Ce are uniformly distributed in the ordered or disordered structures. The MCC-1 leaching results showed that (Gd, Nd)₂(Zr, Ce)₂O₇ pyrochlore ceramic nuclear waste forms had excellent chemical stability, whose elements' normalized leaching rates were as low as 10^-4-10^-7 g·m^-2·d^-1 after 7 days. In particular, the chemical stability of disordered structure was superior to that of ordered structure. It was proposed that the force constant and the closest packing were changed with the structure transformation resulting the chemical stability difference.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2004.04a
• /
• pp.293-300
• /
• 2004

As the structure is taller and its member is larger, the effect of the deformation of Panel zone on the displacement of structure becomes larger. The analysis using the centerline dimensions in the steel moment frame structure can not consider the accurate effect of panel ton And the finite element analysis using infinitesimal solid and shell element is impractical for the total tall building structure. Therefore, this paper proposes the analytical model using linear element in order to be able to evaluate the reasonable deformation of panel zone. the proposed analytical model makes the analysis of the building structure simple and ease because it uses the only linear elements. In addition it can easily incorporate the various parameters affecting the deformation of panel zone. In order to prove the validith of the prosed analytical model, the analysis result using the proposed analytical model is compared with the result using finite element analysis with shell element

• Journal of the Korean Society for Precision Engineering
• /
• v.28 no.8
• /
• pp.894-903
• /
• 2011

In this paper, the capability index is introduced in order to improve the reliability of new concept machine tools and the method to improve the machine accuracy from the analysis of cutting process, statistical methodology and influence factors are proposed. In addition, the rib structure of bed and column in machine tools is analyzed by using the thermal impact method in order to analogize the rib pattern which has the small thermal deformation under thermal boundary condition. In the analysis of column rib structure, thermal boundary condition is separated to heat conduction and heat transfer to appropriate real boundary condition. Finally, performance chart of bed and column rib structure is provided for designer to estimate each rib pattern and select rib structure appropriating to thermal condition.

• Journal of Information Science Theory and Practice
• /
• v.2 no.4
• /
• pp.6-19
• /
• 2014

The description of preserved resources is one of the requirements in digital preservation. The description is generally created in the format of metadata records, and those records are combined to generate information packages to support the process of digital preservation. However, current strategies or models of digital preservation may not generate information packages in efficient ways. To overcome these problems, this research proposed an internal structure of information packages in digital preservation. In order to construct the internal structure, this research analyzed existing metadata standards and cataloging rules such as Dublin Core, MARC, and FRBR to extract the core elements of resource description. The extracted elements were categorized according to their semantics and functions, which resulted in three categories of core elements. These categories and core elements were manifested by using RDF syntax in order to be substantially applied to combine metadata records in digital preservation. Although the internal structure is not intended to create metadata records, it is expected to provide an alternative approach to enable combining existing metadata records in the context of digital preservation in a more flexible way.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2009.09a
• /
• pp.700-709
• /
• 2009

FBG sensor system is applied to the concrete lining structure in Taegu subway. Near the structure, the power cable tunnel construction started. We wanted to measure the deformation of the structure due to the construction by the FBG sensor. The applied sensor has the gauge length of 1 meter to overcome the inhomogeneity of the concrete material with enough length. In order to fix tightly to the structure, the partially stripped parts of the sensor glued to the package and slip phenomenon between fiber and acrylate jacket was prevented. Prestrain of the sensor was imposed by controlling the two fixed points with bolts and nuts in order to measure compressive strain as well as tensile strain. The behavior of subway lining structure could be monitored very well.

• Molecules and Cells
• /
• v.42 no.7
• /
• pp.512-522
• /
• 2019

Chromosomes located in the nucleus form discrete units of genetic material composed of DNA and protein complexes. The genetic information is encoded in linear DNA sequences, but its interpretation requires an understanding of three-dimensional (3D) structure of the chromosome, in which distant DNA sequences can be juxtaposed by highly condensed chromatin packing in the space of nucleus to precisely control gene expression. Recent technological innovations in exploring higher-order chromatin structure have uncovered organizational principles of the 3D genome and its various biological implications. Very recently, it has been reported that large-scale genomic variations may disrupt higher-order chromatin organization and as a consequence, greatly contribute to disease-specific gene regulation for a range of human diseases. Here, we review recent developments in studying the effect of structural variation in gene regulation, and the detection and the interpretation of structural variations in the context of 3D chromatin structure.

• Special Issue of the Society of Naval Architects of Korea
• /
• 2005.06a
• /
• pp.69-75
• /
• 2005

Recently it was reported that the vibration problems on the oil pipe support structure of the crude oil carrier were occurred. in order to investigate the vibration characteristics and the causes of the vibration occasionally. the vibration measurements and impact tests for the oil Pipe structure were carried out. From the measurement results severe vibration was caused by the resonance between the transversal natural frequency of the structure and $6^{th}$ order excitation force of the main engine. Providing the proper countermeasures a series of the vibration analyses were carried out based on the measurement results. From the analysis results, it was concluded that the vibration characteristics of the oil pipe structure were affected by the oil pipes, support structure itself, upper deck structure and the installation spaces and the standard design was established for the crude oil carriers.

• The Journal of Korean Medical History
• /
• v.33 no.2
• /
• pp.89-104
• /
• 2020

The purpose of this research is to build a database structure that can be useful for evidence-based medical practices by constructing the knowledge related to oriental medicine in the classical literature knowledge in a form that can utilize new forms of information technology. As a method, "database" is used as a keyword to search published studies in the field of oriental medicine, research is conducted on classic literature knowledge, and studies describing the contents of the data structure are found and analyzed. In conclusion, the original text DB for the preservation of the original texts and the presentation of the supporting texts should include 'Contents Text', 'Tree Structure', 'Herbal Structure', 'Medicine Manufacture', and 'Disease Structure' tables. In order to search, calculate, and automatically extract expressions written in the original text of the old literature, the tool DB should include 'Unit List', 'Capacity Notation List', 'CUI', 'LUI', and 'SUI' tables. In addition, In order to manage integrated knowledge such as herbal, medicine, acupuncture, disease, and literature, and to implement a search function such as comparison of similarity of control composition, the knowledge DB must contain 'dose-controlled medicine name', 'dose-controlled medicine composition', 'relational knowledge', 'knowledge structure', and 'computational knowledge' tables.