• Proceedings of the Korea Concrete Institute Conference
• /
• 2005.05a
• /
• pp.263-266
• /
• 2005

Many RC structures built without seismic provisions have exhibited brittle shear failures in the beam-column joint area, and resulted in large permanent deformations and structural collapse. This paper presents the results of an experimental investigation pertaining to the use of carbon fiber-reinforced polymer(FRP) for strengthening of RC beam-column connections. The selective upgrade is obtained by choosing different combinations and locations of carbon FRP sheets to determine the effective way to improve the structural performance of joints. Experimental results demonstrate significant improvement of flexural capacity and ductility of beam-column connections originally built without seismic details.

• Korean System Dynamics Review
• /
• v.6 no.2
• /
• pp.117-138
• /
• 2005

The defence industry of the Republic of Korea(ROK) has grown up since 1970, however it is facing a growth hindrance due to its structural problem. Many professionals of defense industry has developed some measures to upgrade and energize the defence industry of ROK, and also the current government is implementing various transformations and new policies under the initiative of cooperative independence defence. But most of papers published so far have some limitations resulting from their qualitative contents. And also it is true for them not to show policy alternatives devised by the system thinking. This paper identifies essential factors of defense industry, then analyze the causal relation among those factors. It also shows the causal loop to identify the politic leverages, on which concrete measures to resolve the structural problems are based.

• Structural Engineering and Mechanics
• /
• v.49 no.5
• /
• pp.631-644
• /
• 2014

Seismic assessment and retrofitting of existing structure is a complicated work that typically requires more sophisticated analyses than performing a new design. Before the implementation of a Code for seismic design of buildings (GBJ 11-89), not enough attention has been paid on seismic performance of structures and a great part of the existing reinforced concrete structures built in China have been poorly designed according to the new version of the same code (GB 50011-2010). This paper presents a case study of seismic assessment of a non-seismically designed reinforced concrete building in China. The structural responses are evaluated using the nonlinear static procedure (the so-called pushover analysis), which requires its introduction within a process that allows the estimation of the demand, against which the capacity is then compared with. The capacity of all structural members can be determined following the design code. Based on the structural performance, suitable retrofitting strategies are selected and implemented to the existing system. The retrofitted structure is analyzed again to check the effectiveness of the rehabilitation. Different types of retrofitting strategy are discussed and classified according to their complexity and benefits. Finally, a proper intervention methodology is utilized to upgrade this typical low-rise non-ductile building.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.9 no.1
• /
• pp.119-126
• /
• 2005

The objective of this paper is to investigate the lining board's capacity for the static load. The test is to inspect the possibility of retrofit and efficiency, which is required to upgrade the structure's capacity and to examine the effects of the improvements of specimen by using structural analysis, and static loading test, respectively. As the result of static loading test for measured stresses and deflections. H type lining board take sufficient load carrying capacity and high stiffness which likes ultimate load, displacement, and bending stresses of intermediate span and top, bottom flange more than 3 times channel type lining board.

• Journal of Ocean Engineering and Technology
• /
• v.30 no.4
• /
• pp.294-302
• /
• 2016

Because of the importance of steel material saving and rational ship structural design due to the rapid increase in steel prices, a ship structural design system was developed for plate members reinforced by doubler plates subjected to biaxial in-plane compressive loads. This paper mainly emphasizes the design system improvement and upgrade according to the change in the in-plane loading condition of the doubler plate from the single load discussed in a previous paper to the biaxial in-plane compressive load discussed in this paper. A direct design process by a structural designer was added to this developed optimized system to increase the design efficiency and provide a way of directly inserting a designer's decisions into the design system process. As the second stage of preliminary steps of doubler design system development, design formulas subjected to these biaxial loads used in the doubler plate design system were suggested. Based on the introduction of influence coefficients $K_t_c$, $K_t_d$, $K_b_d$ and $K_a_d$ based on the variations in the doubler length, breadth, doubler thickness, and average corrosion thickness of the main plate reinforced by the doubler plate, respectively, the design formulas for the equivalent plate thickness of the main plate reinforced by the doubler plate were also developed, and a hybrid design system using these formulas was suggested for the doubler plate of a ship structure subjected to a biaxial in-plane compressive load. Using this developed design system for a main plate reinforced by a doubler plate was expected to result in a more rational reinforced doubler plate design considering the efficient reinforcement of ship plate members subjected to these biaxial loads. Additionally, a more detail structural analysis through local strength evaluations will be performed to verify the efficiency of the optimum structural design for a plate member reinforced by a doubler plate.

• Journal of Korean Society of Rural Planning
• /
• v.9 no.3 s.20
• /
• pp.25-34
• /
• 2003

This study was carried out to propose some useful advices for the improvement policy of the minor rural roads. For the detailed case studies on structural improvement level of the minor rural roads, 5 county areas in Chonnam Province were selected ; Damyang (peri-urban), Gurye(remoter mountainous), Jindo(remotest island), Yuongam(intermediate flat) and Bosung (intermediate semi-mountainous). In each county, the official survey data on pavement types, widths and ratios of district(Myun in Korean) and parish(Ri in Korean) roads were collected. There were no apparent differences between district and parish roads in terms of structural improvement level, while the former was ranked higher than the latter in the minor rural road improvement law, so, the present hierarchial classification system of rural roads should be readjusted. And above a third of minor rural roads in the case study areas did not meet the statutory minimum level of road width, which means the necessity of substantial upgrade of road improvement works in rural areas.

• Human Ecology Research
• /
• v.61 no.3
• /
• pp.475-492
• /
• 2023

This study investigated player responses to microtransactions in freemium Massively multiplayer online roleplaying games (MMORPG), specifically focusing on the game LostArk using English language review data. To this end, structural topic modeling was employed and the following six microtransaction-relevant topics were identified: microtransactions, developer issues, real money trade (RMT), random number generator (RNG) upgrade system, game content, and collectibles & adventure. The first four topics were classified as being "not recommended". However, the proportions of microtransaction-related topics were relatively lower than the other topics. Additionally, this study did not extract keywords related to unfairness and unethical issues in previous microtransaction research. The last two topics, game content, and collectibles & adventure were "recommended" topics, indicating positive functions of microtransactions such as enhancing the game experience by purchasing virtual items. Moreover, it was found that players who do not engage in microtransactions can still be satisfied through continuous game content updates. Additionally, an examination of the interaction effect between time and recommendation status revealed that while the frequency with which the six microtransaction-related topics were mentioned increased over time in the reviews, the ratio of recommendations to non-recommendations varied differently. This study contributes to game-related research by revealing players' authentic opinions on microtransactions in freemium MMORPGs, thereby providing practical implications for game companies.

• Steel and Composite Structures
• /
• v.27 no.3
• /
• pp.327-335
• /
• 2018

This paper presents structural assessment of a steel railway bridge for current condition using modal parameter to upgrade finite element modeling in order to gather accurate result. An adequate monitoring, such as acceleration, displacement, strain monitoring, is important tool to understand behavior and to assess structural performance of the structure under surround vibration by means of the dynamic analysis. Evaluation of conditions of an existing steel railway bridge consist of 4 decks, three of them are 14 m, one of them is 9.7 m, was performed with a numerical analysis and a series of dynamic tests. Numerical analysis was performed implementing finite element model of the bridge using SAP2000 software. Dynamic tests were performed by collecting acceleration data caused by surrounding vibrations and dynamic analysis is performed by Operational Modal Analysis (OMA) using collected acceleration data. The acceleration response of the steel bridge is assumed to be governing response quantity for structural assessment and provide valuable information about the current statute of the structure. Modal identification determined based on response of the structure play significant role for upgrading finite element model of the structure and helping structural evaluation. Numerical and experimental dynamic properties are compared and finite element model of the bridge is updated by changing of material properties to reduce the differences between the results. In this paper, an existing steel railway bridge with four spans is evaluated by finite element model improved using operational modal analysis. Structural analysis performed for the bridge both for original and calibrated models, and results are compared. It is demonstrated that differences in natural frequencies are reduced between 0.2% to 5% by calibrating finite element modeling and stiffness properties.

• Journal of The Korea Institute of Healthcare Architecture
• /
• v.18 no.3
• /
• pp.51-59
• /
• 2012

Over a past century, the continuity in post-earthquake serviceability of medical facilities has been demonstrated to be essential for sustaining a society and/or a nation stable. However, not many countries including Korea have paid appropriate attention to such a lesson learned from the previous experiences of the countries located in high seismicity for various reasons, one of which may be the lack of social consensus in allocating a portion of the resources to the earthquake preparedness. As a result, an earthquake-related policy might have been pushed away out of the list of priority in the government agenda. Therefore, the present paper attempts to persuade the public general, experts and government officials together to seek a way to upgrade the seismic safety of the country a step forward by enhancing the seismic performance of medical facilities. For this the framework of seismic design codes and standards for medical facilities, and Californian experience in managing the seismic performance enhancement program and U.S.-Italian collaborative study to improve the seismic safety of Italian hospitals are reviewed. Finally, a list of further researches and practices to perform for seismic enhancement of medical facilities in Korea are suggested.

• The Journal of Korean Association of Computer Education
• /
• v.20 no.5
• /
• pp.79-88
• /
• 2017

To upgrade the subjective question grading, we need the syntactic-semantic analysis to analyze syntatic-semantic relation between words in answering. However, since the syntactic-semantic tree has structural and semantic relation between words, we can not apply the method calculating the similarity between vectors. This paper suggests the comparing system with syntactic-semantic tree which has structural and semantic relation between words. In this thesis, we suggest similarity calculation principles for comparing the trees and verify the principles through experiments. This system will help the subjective question grading by comparing the trees and be utilized in distinguishing similar documents.