• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.1C
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• pp.65-76
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• 2010

Recent earthquake events revealed that severe seismic damages were concentrated mostly at sites composed of soil sediments rather than firm rock. This indicates that the site effects inducing the amplification of earthquake ground motion are associated mainly with the spatial distribution and dynamic properties of the soils overlying bedrock. In this study, an integrated GIS-based information system for geotechnical data was constructed to establish a regional counterplan against ground motions at a representative metropolitan area, Seoul, in Korea. To implement the GIS-based geotechnical information system for the Seoul area, existing geotechnical investigation data were collected in and around the study area and additionally a walkover site survey was carried out to acquire surface geo-knowledge data. For practical application of the geotechnical information system used to estimate the site effects at the area of interest, seismic zoning maps of geotechnical earthquake engineering parameters, such as the depth to bedrock and the site period, were created and presented as regional synthetic strategy for earthquake-induced hazards prediction. In addition, seismic zonation of site classification was also performed to determine the site amplification coefficients for seismic design at any site and administrative sub-unit in the Seoul area. Based on the case study on seismic zonations for Seoul, it was verified that the GIS-based geotechnical information system was very useful for the regional prediction of seismic hazards and also the decision support for seismic hazard mitigation particularly at the metropolitan area.

• Korean Association for Visual Culture
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• v.19
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• pp.189-221
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• 2012

This thesis investigates the development of optical instruments in the 19th century, before the birth of the cinema, and the principle of the perception of moving images. For this purpose it traces the development stages of the optical instruments which demonstrated 'illusion of movement' from 1820s when the 'persistence of vision' had begun to be researched by scientists. Then, it examines the theory of the 'persistence of vision' or 'afterimage effect' known as the principle in the perception of illusion of movement produced from moving images. The optical instruments in the 19th century that presented the illusion of movement began with the Thaumatrope (double-sided picture disc), and appeared from the Phenakistiscope/Stroboscope (revolving disc), the Zoetrope (revolving drum) and the Praxinoscope (mirror-reflexive revolving drum), and in 1892 the Projection-Praxinoscope presented firstly the moving pictures (animation) on the screen. According to the research of psychology and physiology in the early 20th century it has been recognized that the 'afterimage effect' theory is not sufficient to explain the perception of illusion of movement from the moving images which is closely related to the particularity of the visual perception system of the human eyes. Since then, the Phi-phenomenon suggested 1912 by the Gestalt psychologist, Max Wertheimer (1880-1943), is regarded as the most persuasive theory until now, although it is still imperfect.

• Korean Journal of Legislative Studies
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• v.27 no.2
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• pp.71-109
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• 2021

The purpose of this study is to find out what factors influence lawmakers' voting decisions in the plenary session. In particular, the study examines causes and characteristics of waffling and strategic waffling, which express opposition or abstention in a discharge petition or a vote at the plenary session despite participating in a bill sponsorship. The study on waffling is meaningful because it has not been covered in previous literatures. To this end, the Gadeokdo New Airport Special Act, which the National Assembly passed in February 2021, was set as an analysis target. The study examined the factors that affected legislators' voting decisions and participation in bill sponsorship and who were related with waffling. Statistical results showed that the age variable influenced the motion of the bill while seniority and party affiliation had an effect on the participation of the bill. Likewise, the study found that party affiliation and district had an influence on the approval of the bill. In addition, the analysis of waffling showed that lawmakers with higher seniority tended not to participate in the vote. It could be interpreted that lawmakers with more legislative experience judged that they would benefit from strategic waffling. There is a limit to understanding lawmakers' decision-making and waffling through a limited analysis of the Gadeokdo New Airport bill. However, given that lawmakers tend to choose avoidance strategies in ambiguous situations, and given the high intelligence of lawmakers who know better than anyone about the future impact of a new bill, the decision-making shown by lawmakers in each stage of the situation is a prudent judgment gained from their experience. It indicates that it is necessary to research the legislative activities of lawmakers in various ways.

• (The) Research of the performance art and culture
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• no.39
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• pp.637-667
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• 2019

I have researched in the field the religious and performance culture of Indonesia through the musical iconography of Borobudur. There are many kinds of musical instruments which belong to India or Indonesia, performers being either court or folk musicians. Contemporary south-east Asian Indonesia has a broad religious heritage. Most of the population is Muslim, but the culture and customs are rooted in Indian Ramayana. I discovered, for example, the same percussion instruments played on a person's knees. I also came across similar string instruments with long and elliptical resonance casks on the iconography of the Incense Burner and Byam temple stone pagoda of Beakje dynasty in Korea and in Borobudur in Indonesia. The two musical instruments can not be found in other countries, such as Silla, Koguryŏ, China or the silk road area, but only Indonesia or India. This suggests that Beakje Buddhism is from the southern regions rather than China. I also discovered the same dancing motion with the court performers on the iconography of Borobudur, and the same musical instrument and performance in the Gamelan in today's Indonesian performance. Despite a disjuncture between the people and their past, the Shailendra Buddhism is alive in people's life and culture in the present day. So we can discover some familiarities between Indonesia's Gamelan and the percussional performance in Korean Buddhist rituals.

• Journal of the Korea Computer Graphics Society
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• v.29 no.5
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• pp.1-9
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• 2023

The control technology of animatronics is an interesting topic explored in various fields, including engineering, medicine, and art, with ongoing research efforts. The conventional method for controlling the movement of animatronics is to use electric motors installed inside the body. However, this method is difficult to apply when expressing a narrow space inside the body. In this study, a method of using external forces instead of installing mechanical devices inside the body was proposed to control the movement of a thin and long tentacle organism. Specifically, in this study, the joint body of animatronics was made of magnetic metal material so that it could be affected by the force of an externally installed electromagnet. The strength of the electromagnet was controlled by a PID controller to enable real-time control of the position of the animatronics body. In addition, the magnet was made to rotate, and the speed of rotation was changed to create various movements. Through virtual environment simulations, our experiments demonstrate the superiority of the proposed method, showcasing real-time control by users and the creation of animations in various styles.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.6
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• pp.688-696
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• 2023

In the present study, free roll decay and resistance performances of fishing vessels were evaluated with the combinations and variations of in the parameters of appendages which are attached to improve motion performance of fishing vessels. Computational Ffluid Ddynamics was used to perform free roll decay and resistance analysis. The roll period and decay coefficient were derived by the variations in the combination and dimensions of the primary appendages of the bilge keel and the under keel. It was observed thatThe variations of in the length of the under keel did not significantly impact to the roll damping coefficient. Conversely, for the bilge keel, an increase in the length and angle resulted in an increase in the roll damping coefficient. Comparison of resistance performance was additionally assessed among the selected hulls with the appendages and bare hull. The resistance of the hull with the appendages was higher than that of the bare hull due owing to the changes of in the pressure on the surface of the hull and trim angle. Throughout the present study, the impact of appendage parameter and arrangement on the free roll decay and resistance performance of fishing vessels were was assessed,. which This will be beneficial for the application of appendages to fishing vessels.

• Journal of Korean Medicine Rehabilitation
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• v.33 no.4
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• pp.45-59
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• 2023

Objectives The aim of this study was to analyze the trends of researches on oriental medicine treatments for supraspinatus tendinopathy. Methods We used five databases for searching researches; Korean studies Information Service System, Oriental Medicine Advanced Searching Integrated System, Research Information Sharing Service, PubMed, and China National Knowledge Infrastructure. Only randomized controlled trials suitable for the subject were selected. The methodological quality of included randomized controlled trials (RCTs) was assessed by the Cochrane risk of bias tool. Results Twenty randomized controlled trials were analyzed. There were 9 types of treatment interventions; acupuncture, acupotomy, pharmacopuncture, electroacupuncture, fire needling, warming needle, catgut-embedding therapy, herbal medicine, cupping. The most frequently used treatment intervention was acupuncture and acupotomy. There were 9 outcome measurements including visual analog scale (VAS), Constant-Murley Score (CMS), and range of motion. The most used measurement was VAS. As a result of meta-analysis, acupuncture was more effective than control group in VAS. Additionally, acupotomy was clinically significant compared to control groups in VAS and CMS. Conclusions In this review, we analyzed researches on effectiveness of oriental medicine for supraspinatus tendinopathy. A provisional conclusion can be produced that acupuncture and acupotomy showed beneficial effect to supraspinatus tendinopathy. Although there were some RCT studies, many of them had a high risk of bias, so it is hard to conclude that our study can include overall clinical status. Further well-designed trials are needed.

• Journal of The Korean Society of Integrative Medicine
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• v.12 no.2
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• pp.47-53
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• 2024

Purpose : This study investigated the effects of concentric and eccentric contractions on muscle strength using an isokinetic dynamometer (ID) in college students in their 20s. It aimed to understand the impact of differences between the dominant and non-dominant sides on strength asymmetry and to elucidate the clinical implications of these differences to establish an appropriate posture and environment for patients. Methods : The experiment was conducted with 30 healthy adult participants. Prior to the experiment, participants underwent a warm-up targeting the shoulders, and efforts were made to eliminate factors that could potentially influence the measurement results. Subsequently, the maximum safe range of motion of shoulder joint abduction, extension, and flexion was measured using an isokinetic muscle function testing device. Muscle strength was assessed using concentric and eccentric contractions alternating between the dominant and non-dominant sides, and paired sample t-tests were used for the analysis. Results : There was no significant difference between bilateral peak torques for eccentric contraction in shoulder joint abduction, extension, and flexion (p>0.05). There was also no significant difference between bilateral peak torques for concentric contraction in shoulder joint abduction, extension and flexion (p>0.05). Conclusion : This study found no statistically significant difference in muscle strength between the dominant and non-dominant sides during concentric and eccentric contractions. However, previous studies have shown significant differences between the dominant and non-dominant sides during eccentric and concentric contractions during internal shoulder rotation in the general population, as well as significant differences in the upper trapezius muscle. Therefore, further research is needed to support the application of different intensities for bilateral muscle strengthening exercises in clinical practice.

• Advances in nano research
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• v.16 no.6
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• pp.565-577
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• 2024

Vibration investigation of fluid-filled functionally graded cylindrical shells with ring supports is studied here. Shell motion equations are framed first order shell theory due to Sander. These equations are partial differential equations which are usually solved by approximate technique. Robust and efficient techniques are favored to get precise results. Employment of the Rayleigh-Ritz procedure gives birth to the shell frequency equation. Use of acoustic wave equation is done to incorporate the sound pressure produced in a fluid. Hankel's functions of second kind designate the fluid influence. Mathematically the integral form of the Langrange energy functional is converted into a set of three partial differential equations. A cylindrical shell is immersed in a fluid which is a non-viscous one. These shells are stiffened by rings in the tangential direction. For isotropic materials, the physical properties are same everywhere where the laminated and functionally graded materials, they vary from point to point. Here the shell material has been taken as functionally graded material. After these, ring supports are located at various positions along the axial direction round the shell circumferential direction. The influence of the ring supports is investigated at various positions. Effect of ring supports with empty and fluid-filled shell is presented using the Rayleigh - Ritz method with simply supported condition. The frequency behavior is investigated with empty and fluid-filled cylindrical shell with ring supports versus circumferential wave number and axial wave number. Also the variations have been plotted against the locations of ring supports for length-to-radius and height-to-radius ratio. Moreover, frequency pattern is found for the various position of ring supports for empty and fluid-filled cylindrical shell. The frequency first increases and gain maximum value in the midway of the shell length and then lowers down. It is found that due to inducting the fluid term frequency result down than that of empty cylinder. It is also exhibited that the effect of frequencies is investigated by varying the surfaces with stainless steel and nickel as a constituent material. To generate the fundamental natural frequencies and for better accuracy and effectiveness, the computer software MATLAB is used.

• Journal of the Korea Computer Graphics Society
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• v.30 no.3
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• pp.23-41
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• 2024

Recently, various virtual avatar music content that showcases singing and dancing have been produced, and as virtual artists gain popularity, offline virtual avatar concerts have also emerged. However, there are few examples of virtual avatar band content where avatars play instruments. In addition, offline virtual avatar concerts using large screens at the front are limited in their ability to utilize the fantastical effects and high degree of freedom unique to virtual reality. In this paper, inspired by these limitations of virtual avatar music content, we introduce the production case of virtual avatar band content and immersive interactive concert of virtual band idol Verse'day. Firstly, we present a case study on creating band performance animations and music videos using motion capture systems and real-time engines. Then, we introduce a production case of an immersive interactive concert using projection mapping technology and a light stick that allows real-time interaction in an offline concert. Finally, based on these production cases, we discussed the future research directions of developing virtual avatar music content creation. We expect that our production cases will inspire the creation of diverse virtual avatar music content and the development of immersive interactive offline virtual avatar concerts in the future.