• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.7
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• pp.1259-1266
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• 2022

Recently, due to the specialization of structural design standards and evaluation methods, the classification rules are being integrated. A good example is the common international rules (CSR). However, detailed regulations are presented only for the cargo hold area where the longitudinal load is greatly applied, and no specific evaluation guidelines exist for the bow and stern structures. Structural design of the mentioned area is carried out depending on the design experience of the shipbuilder, and because no clear standard exists even in the classification, determining the root cause is difficult even if a structural damage problem occurs. In this study, an engineering-based solution was presented to identify the root cause of representative cases of buckling damage that occurs mainly in the stern. Buckling may occur at the panel wall owing to hull girder bending moment acting on the stern structure, and the plate thickness must be increased or vertical stiffeners must be added to increase the buckling rigidity. For structural strength verification based on finite element analysis modeling, reasonable solutions for load conditions, boundary conditions, modeling methods, and evaluation criteria were presented. This result is expected to be helpful in examining the structural strength of the stern part of similar carriers in the future.

• Journal of International Area Studies (JIAS)
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• v.14 no.3
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• pp.135-156
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• 2010

While there are a few ways of giving meanings to the term, "Altai" ranging from a language family to a national residing around the Altai Mountains in Russian Federation, and to the people speaking the language or the whole area where they live, there have been controversial debates whether it is a meaningful categorization. This paper argues that the basic cause lying beneath the controversies is the underdevelopment of the subject that identifies itself as a representative of the whole area where the Altaic language family is spoken. It might be true, as some Korean and Russian scholars insist, that what deserves to be called Altaic culture (or civilization) has provided a common culture and mutual interactions with the people. However, the Altaic people failed to constitute themselves as a meaningful modern group, that is a nation, and they did not fully develop national consciousness, As a result, although their way of life may be regarded as an origin of various cultures across North-East Asia, Altaic culture is not sufficient to give a momentum to claim for cultural initiative in the region. This comes at least partly from the reconfiguration of ethnic identity through a Soviet type of modernization and its geopolitical situation surrounded by super-powers such as China and Russia, as well as belated import of religions such as Buddhism and Christianity. From a wide perspective, the trouble about delimiting an area is not unique in Altai, but universally found in anywhere, as far as area studies are concerned. The delimitation of an area is not a natural outcome of physical environment but an artificial production of how cultural-political relationships have been distributed. Therefore, while the case of Alai has its own specificities, its implications that a national or regional boundary in area studies should not be taken for granted may be applied to other areas.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.3
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• pp.110-115
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• 2023

During the Hg₂Br₂ physical vapor transport process, with increasing the partial pressure of component B, P_B from 40 Torr to 200 Torr, a unicellular convective flow structures move from the crystal growth region to the center region in the vapor phase. The boundary layer flow is dominant for P_B = 40 Torr, and the core region flow is dominant for P_B = 200 Torr. The flow in the vapor phase shows a three-dimensional convective flow structure with a single cell (unicellular) for P_B = 40 Torr and 200 Torr, exhibits an asymmetrical flow with respect to the x, y central axis under the horizontally oriented configuration with an aspect ratio (length-to-width) of 3 and linear conducting walls. The critical temperature difference between the source and crystal region is about 30 K. The total molar flux of Hg₂Br₂ increases with the temperature difference until the total molar flux reaches the critical value. At the critical total molar flux, the total molar flux abruptly decreases.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.2
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• pp.249-256
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• 2022

Various studies are being actively conducted to show that the real-time visualization technology that combines BIM (Building Information Modeling) and AR (Augmented Reality) helps to increase construction management decision-making and processing efficiency. However, when large-capacity BIM data is projected into AR, there are various limitations such as data transmission and connection problems and the image cut-off issue. To improve the high efficiency of visualizing, a mesh optimization algorithm based on the k-nearest neighbors (KNN) classification framework to reconstruct BIM data is proposed in place of existing mesh optimization methods that are complicated and cannot adequately handle meshes with numerous boundaries of the 3D models. In the proposed algorithm, our target BIM model is optimized with the Unity C# code based on triangle centroid concepts and classified using the KNN. As a result, the algorithm can check the number of mesh vertices and triangles before and after optimization of the entire model and each structure. In addition, it is able to optimize the mesh vertices of the original model by approximately 56 % and the triangles by about 42 %. Moreover, compared to the original model, the optimized model shows no visual differences in the model elements and information, meaning that high-performance visualization can be expected when using AR devices.

• Journal of Korea Entertainment Industry Association
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• v.13 no.7
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• pp.15-23
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• 2019

This paper aims to identify the characteristics implied in the process of change of Stephen Sondheim's musical style and to derive the structural communication tools that connect the creator and audience and the implications. The strategies that appear in Sondheim's musical works are the following. First, Sondheim's early musical works follow the principles of book musical and emphasize the integration faithful to the basic elements such as the rhythm and meaning of the lyrics. Second, in the era of early postmodernism, Sondheim attempts the principle of extreme deconstruction through the concept musical Company and pursues rational thought through fragmented dramatic flow. Third, while maintaining dramatic linearity to overcome the lack of immersion caused by extreme deconstruction, Sondheim realizes a more elaborate and formalized fusion style of the principles of integration and deconstruction through the choruses and the songs of the characters in Little Night Music and Sweeney Todd. Finally, Sondheim attempts multiple experiments to break down the boundaries of act and scene and to express new subject matters through his works such as Sunday Park with George and Into the Woods. In conclusion, Sondheim's fusion experiments and strategies are the process of finding a framework and a medium of communication to induce dramatic immersion of audience and at the same time create rational thinking about social problems to deliver the message of the creative work with the leading aesthetics of the modern musical's box-office success.

• 지역과문화
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• v.6 no.4
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• pp.23-45
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• 2019

The main research is on how to find source stories and develop and utilize content that will properly show the value of Panmunjom and the surrounding DMZ on the Korean Peninsula, which are receiving worldwide attention. Three methods were used as research for the high-end branding of Panmunjom and the surrounding DMZ. The first is the interest of prospective visitors through the travel cycle, using Joseph Campbell's "The Hero's Journey." The second was to incorporate Roland Bart's "third meaning" into the subjective travel and emotional stimulation, which is the trend of modern travel. The third introduced Kevin Lynch's theory and tried to place five elements of the path, edge, district, node and landmark in the core location of Panmunjom. Through the study, the excavation of contents in Panmunjom and the surrounding DMZ needs to be collected to a third meaning using a direct interview method that listens to the stories of related figures as well as organizing historical events. The priority should be given to those over the age of 80 and interviews should be conducted at least three times and over three generations. The process of building it into an archive, selecting a story, and then going through a culture collage and networking and branding takes place in five stages. This can create a virtuous circle of content processing, content utilization, job creation in the region and revitalizing the local economy through discovery of source stories and storytelling. Content development should be able to touch sensibility while saving time, history, place, originality and sincerity. Taking the center between tourism and travel, development and damage concerns, a careful but long-term plan and large-scale discovery of source stories should be made, and a consensus should be formed on the need for proper storytelling.

• Journal of Korean Tunnelling and Underground Space Association
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• v.25 no.6
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• pp.403-421
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• 2023

As the number of underground structures has increased in recent decades, it has become crucial to predict geological hazards ahead of a tunnel face during tunnel construction. Consequently, this study developed a finite element (FE) numerical model to simulate electrical resistivity surveys in tunnel boring machine (TBM) operations for predicting mixed ground conditions in front of tunnel faces. The accuracy of the developed model was verified by comparing the numerical results not only with an analytical solution but also with experimental results. Using the developed model, a series of parametric studies were carried out to estimate the effect of geological conditions and sensor geometric configurations on electrical resistivity measurements. The results of these studies showed that both the interface slope and the difference in electrical resistivity between two different ground formations affect the patterns and variations in electrical resistivity observed during TBM excavation. Furthermore, it was revealed that selecting appropriate sensor spacing and optimizing the location of the electrode array were essential for enhancing the efficiency and accuracy of predictions related to mixed ground conditions. In conclusion, the developed model can serve as a powerful and reliable tool for predicting mixed ground conditions during TBM tunneling.

• Journal of Korean Tunnelling and Underground Space Association
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• v.26 no.3
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• pp.169-189
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• 2024

In the current work, a series of three-dimensional finite element analyses have been carried out to understand the behaviour of pre-existing single piles and pile groups to adjacent Shield TBM tunnelling by considering various reinforcement conditions. The numerical modelling has analysed the effect of the pile cutting, ground reinforcement and pile cap reinforcement. The analyses concentrate on the ground settlements, the pile head settlements, the axial pile forces and the shear stress transfer mechanism at the pile-soil interface. In all cases of the pile tips supported by weathered rock, the distributions of shear stresses presented a similar trend. Also, when the pile tips were cut, tensile forces or compressive forces were induced on the piles depending on the relative positions of the piles. Furthermore, when the pile tips are supported by weathered rock, approximately 70% of the load is supported by surface friction, and only the remaining 30% is supported by the pile tip. Furthermore the final settlement of the piles without reinforcement showed approximately 70% more settlement than the piles for which ground reinforcement is considered. It has been found that the ground settlements and the pile settlements are heavily affected by the pile cutting and reinforcement conditions. The behaviour of the single pile and group piles, depending on the pile cutting, conditions of ground and pile cap reinforcement, has been extensively examined and analysed by considering the key features in great details.

• Journal of the Korean GEO-environmental Society
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• v.25 no.4
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• pp.21-28
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• 2024

In this study, a polyhedral domain decomposition method for Smoothed Particle Hydrodynamics (SPH) analysis is introduced. SPH which is one of meshless methods is a numerical analysis method for fluid flow simulation. It can be useful for analyzing fluidic soil or fluid-structure interaction problems. SPH is a particle-based method, where increased particle count generally improves accuracy but diminishes numerical efficiency. To enhance numerical efficiency, parallel processing algorithms are commonly employed with the Cartesian coordinate-based domain decomposition method. However, for parallel analysis of complex geometric shapes or fluidic problems under dynamic boundary conditions, the Cartesian coordinate-based domain decomposition method may not be suitable. The introduced polyhedral domain decomposition technique offers advantages in enhancing parallel efficiency in such problems. It allows partitioning into various forms of 3D polyhedral elements to better fit the problem. Physical properties of SPH particles are calculated using information from neighboring particles within the smoothing length. Methods for sharing particle information physically separable at partitioning and sharing information at cross-points where parallel efficiency might diminish are presented. Through numerical analysis examples, the proposed method's parallel efficiency approached 95% for up to 12 cores. However, as the number of cores is increased, parallel efficiency is decreased due to increased information sharing among cores.

• The Korean Journal of Petroleum Geology
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• v.5 no.1_2 s.6
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• pp.36-47
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• 1997

This study presents multi-variable sequence model for a broader application of sequence concept proposed by Exxon group. The concept of the multi-variable model is based on the fact that internal organization and boundary type of the sequences are determined by three varying factors including 3rd-order cycles of eustasy, and tectonic movement and sediment influx with 2nd-order changes. Instead of Exxon group's systems tracts, this model adopts parasequence sets as the fundamental building blocks of the sequence, because they are descriptive stratigraphic units simply defined by internal stacking pattern, reflecting interactions of accommodation and sediment influx. Seven sequence types which vary in number and type of internal parasequence sets are formulated as associations of four types of accommodation development and three grades of sediment influx. In the southwestern margin of Ulleung Basin, the multi-variable sequence analysis of shelf-slope sequence shows systematic changes in stratal patterns and the numbs, of constituent parasequence sets (i.e. sequence type). These changes are interpreted to reflect temporal and spatial changes in type and rate of tectonic movement and sediment influx, as a result of back-arc opening and closing. During the back-arc opening, rapid subsidence, continuous rise of relative sea level, and high sediment influx gave rise to sequences dominantly of single progradational parasequence set. In the early stage of back-arc closing accompanied by local contractional deformation, different types of sequences contemporaneously formed depending on the spatial changes in tectonically-controlled accommodation and influx rates. During the subsequent slow back-arc subsidence, rise-dominated relative sea-level cycle was coupled with moderate to high sedimentation rate to have resulted in sequences consisting of $2~3$ parasequence sets.