• Journal of Ocean Engineering and Technology
• /
• v.22 no.4
• /
• pp.72-77
• /
• 2008

General aspects of deepwater petroleum exploration and production were identified and related technical challenges were addressed. Historical perspectives, insight, processes, and engineering applications are reviewed to enhance the design capability of the domestic offshore industry. The technical challenges and unique aspects of deepwater exploration and production were identified. The assessment of deepwater exploration, drilling, and production systems is a key stage for performing the front end engineering design (FEED). The global trends in deepwater development, including the feasibility for Korea, were reviewed.

• Earthquakes and Structures
• /
• v.5 no.2
• /
• pp.207-223
• /
• 2013

Practical seismic assessment and design of retrofit for the multitude of small ecclesiastical monuments that abound in the Balkans is the subject of this work. Application of the proposed procedures and methodologies are illustrated in an example case study, a small byzantine church located in Western Greece, which is the region with the highest seismicity in Europe. The church, known as the Fragavilla Monastery, had remained almost undamaged for 800 years, until 1993 when the Pyrgos earthquake caused critical damage mainly in the vaults. Linear elastic analysis to the recorded ground motion, capped by a biaxial failure criterion reproduced the developed damage. The same modelling and analysis procedure was subsequently used for assessment of the intended retrofitting measures. Proposed retrofitting measures included mitigation of the undesirable implications of past interventions along with a combination of strengthening schemes with externally bonded AFRPs strategically placed in the structure. The effectiveness of the proposed solutions is gauged by successful reduction of stress intensity in the critical regions and mitigation of stress localization throughout the structure.

• Journal of Korean Association for Spatial Structures
• /
• v.15 no.3
• /
• pp.69-76
• /
• 2015

Cheomseongdae is the masonry stone structure with the cultural and historical values. But, this structure has the various damages such as cracks, gaps, slope variations and ground subsidence. So, the interests for the safety security in the structural parts have been increased. Therefore, this study performs the structural modelling which considers the several damage cases, and then evaluates the structural behavior characteristics through the discrete element analysis. Especially, this study checks the swelling and displacement gap of the whole structure and the separation between the neighboring members.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2006.04a
• /
• pp.437-444
• /
• 2006

Recently, as large structures become lighter and more flexible, the necessity of structural control for reducing excessive displacement and acceleration due to seismic excitation is increased. As a means to minimize seismic damages, various base isolation systems are adopted or considered for adoption. In this study, a base isolation system using Magneto-Sensitive(MS) rubbers is proposed and shown to effectively protect structures against earthquakes. The MS Rubber is a class of smart controllable materials whose mechanical properties change instantly by the application of a magnetic field To demonstrate the advantages of this approach, the MS Rubber isolation system is compared to Lead-Rubber Bearing(LRB) isolation systems and judged based on computed responses to several historical earthquakes. The MS Rubber isolation system is shown to achieve notable decreases in base drifts over comparable passive systems with no accompanying increase in base shears or in accelerations imparted to the superstructure.

• Earthquakes and Structures
• /
• v.10 no.6
• /
• pp.1391-1404
• /
• 2016

Peninsular Malaysia lying on the stable Sunda Plate has traditionally been considered safe with low to moderate seismicity. However, far field Sumatran mega-earthquakes have been shown to be capable of triggering ground motions felt in high rise structures in the major Malaysian cities while seismic impact from local earthquakes of moment magnitude 3.8 have reportedly induced nominal structural damages to nearby buildings. This paper presents an overview of the recent seismic activities in and around Peninsular Malaysia with reference to prominent earthquakes generated by far field interplate and local intraplate sources. Records of ground motion data and seismic hazard assessment (SHA) results available in the literature have been analyzed and discussed. The peak ground acceleration (PGA) values from historical records for few local intraplate events were observed to be higher than those for the events from Sumatran Subduction Zone. This clearly points to the need for a detailed and comprehensive SHA incorporating both far field and local sources. Such an analysis would contribute the knowledge required for secure and reliable infrastructure design and safeguard the Malaysian people and economy.

• Earthquakes and Structures
• /
• v.27 no.3
• /
• pp.239-250
• /
• 2024

Traditional immovable cultural assets are significant in terms of societal memory and cultural continuity. Therefore, it is essential to preserve their original qualities without alteration while also assessing their resilience under various influences. This study aims to document the Kırklareli Museum building and conduct a performance analysis for potential earthquake scenarios. To this end, surveys of the structure were conducted, on-site inspections were carried out, and ground and material properties were determined for use in the analysis. The 3D model of the structure was prepared to understand its behavior during earthquakes. The analysis results indicate that there will be no damage to the structure. However, it should be noted that damage could occur in the event of a more severe earthquake than the design earthquake specified by the regulations. This study is significant not only for encompassing the museum structure but also for providing a comprehensive evaluation by determining all material properties.

• Journal of the Korean Society of Costume
• /
• v.62 no.6
• /
• pp.182-199
• /
• 2012

The purpose of this study is to analyze the actual status of costume exhibitions displayed in architectural structures heritage today to examine if they play proper roles as visual materials and suggest the necessity of post-management for comfortable viewing. This is significant in that it makes costume exhibitions function as educational culture contents to let Korean and also foreign viewers know of our costume culture properly. As a research method, the database of the Office of Cultural Properties homepage was used to extract anything related to the lives of figures during the Chosun Dynasty among the architectural structures heritages in Seoul, Incheon, and Gyeonggido. By doing so, the costume exhibitions were able to be examined among them. With field investigation and interviews of related institutions, this study examined the current status of costume exhibitions, planning of exhibitions, and post-management. Also, they found costume exhibitions that were not right for the era, and suggested ways that were more appropriate for them. The results of this study were as follows : First, according to the third selection results, there were only six among 71 places where three districts of the architectural structures heritage were present. This is a very small quantity of places when compared with the total number of architectural structures heritage. Second, as a result of the current condition investigation, the costume exhibition in the Architectural Structures Heritage is not nearly enough for a historical investigation, and almost all polluted costumes were not displayed in suitable environments for an exhibition. Therefore, qualified managers who have expertise in exhibition planning were needed to be trained to do a post-management follow up. Furthermore, it is important to systematically reorganize post-management methods. Third, the two selected places(Haepung-buwongun-yuntaegyeong-jaesi and Sunaedong-gaok) were thought not to be right for the era among the six places with costume exhibitions, and suggestions such as flat-drawing and illustration were made.

• The Journal of the Korea Contents Association
• /
• v.13 no.6
• /
• pp.9-19
• /
• 2013

In this paper, we develop a Spatio-Temporal graph as of a key component of our knowledge representation Scheme. We design an integrated representation scheme to depict not only present and past but future in parallel with the spaces in an effective and intuitive manner. An event in general occupies not only a space but a time. Hence a crucial premise for the simulation of virtual situations is to position events in the multi-dimensional context, that is, 3-D space extended by the temporal dimension. Furthermore an event tends to have physical, social and mental aspects intertwined. As a result we need diverse information structures and functions to model entities and relations associated with events and to describe situations in different stances or perspectives of the virtual agents. These structures and functions are implemented in terms of integrated and intuitive representation schemes at different levels such as Ontology View, Instance View, ST View, Reality View. The resulting multi-dimensional comprehensive knowledge structure accommodates multi-layered virtual world developing in the time to maximize the diversity of situations in the historical context. The viability of this knowledge representation scheme is demonstrated with a typical scenario applied to a simulator implemented based on the ST Graph. The virtual stage based on the ST graph can be used to provide natural contexts for situated learning or next-generation simulation games.

• Journal of the Daesoon Academy of Sciences
• /
• v.35
• /
• pp.393-426
• /
• 2020

In the past, holy sites were mainly designated on a basis of archaeological norms and endowed with a specific fixed identity according to historical, religious, and contextual interpretations. However, approaches to these sites are more flexible in recent times. These locations transcend the boundaries of space and time to enable the experience of diverse transformation and reveal multiple religious identities which are embedded in the complex interaction between power and authority. In this regard, the dynamic meanings of the religious symbology of Daesoon Jinrihoe's temple complexes, imagery, and the spatial structures enable us to grant them a new identity by re-establishing these structures as World Heritage sites. Temple complexes (dojang) correspond to the outstanding universal values identified by UNESCO in that the spiritual activities conducted at these holy sites draw the same attention as would be drawn by historical value. In this context, this study aims to explore the potential for Daesoon Jinrihoe's temple complexes to be designated UNESCO world heritage sites. To carry out this study, existing religious heritage sites such as Mount Athos Monasteries in Greece and Lumbini in Nepal are examined as case studies, and the operational plan, conservation, protection of relics, and interaction with its neighboring community and tourists are likewise closely examined in this study.

• Smart Structures and Systems
• /
• v.31 no.5
• /
• pp.485-500
• /
• 2023

Machine learning-based structural health monitoring (ML-based SHM) methods are researched extensively in the recent decade due to the availability of advanced information and sensing technology. ML methods are well-known for their pattern recognition capability for complex problems. However, the main obstacle of ML-based SHM is that it often requires pre-collected historical data for model training. In most actual scenarios, damage presence can be detected using the unsupervised learning method through anomaly detection, but to further identify the damage types would require prior knowledge or historical events as references. This creates the cold-start problem, especially for new and unobserved structures. Modal-based methods identify damages based on the changes in the structural global properties but often require dense measurements for accurate results. Therefore, a two-stage hybrid modal-machine learning damage detection scheme is proposed. The first stage detects damage presence using Principal Component Analysis-Frequency Response Function (PCA-FRF) in an unsupervised manner, whereas the second stage further identifies the damage. To solve the cold-start problem, mode shape assessment using the first mode is initiated when no trained model is available yet in the second stage. The damage identified by the modal-based method would be stored for future training. This work highlights the performance of the scheme in alleviating the cold-start issue as it transitions through different phases, starting from zero damage sample available. Results showed that single and multiple damages can be identified at an acceptable accuracy level even when training samples are limited.